by Ronald Knox

(Click title for Gutenberg text version online)
This 1928 thriller is loosely based around Shifford Lock

I say 'loosely based around Shifford Lock' and the whole identification may be a mistake. But the author certainly knew his Thames and it is certainly the Thames above Oxford that he describes. This is the map given in the book:

"The Footsteps at the Lock" by Ronald Knox
If the loose identification with Shifford Lock is correct then the map has been turned through 90 degrees. Up is East!

'SHIPCOTE LOCK' [SHIFFORD LOCK] - only it's at the wrong end of the weir stream! Most locks and weirs are at the downstream end of any lock cut to avoid the build up of silt. The big exception is St John's Lock (where there is a very muddy cut below the lock!)
'MILLINGTON BRIDGE' [TADPOLE BRIDGE] - some of the plot involves an inn there which in real life is THE TROUT
'THE GUDGEON' [THE ROSE REVIVED] - There is of course another candidate: THE MAYBUSH. However the Rose Revived seems to fit best

I shall avoid the plot itself and look at the descriptions and geography.
The Villages and station fit less well though with exceptions the roads are more or less right.
Chapter II introduces the lock -

The morning sun shone on the upper reaches of the Thames with the hazy glow that recalls a night of rain and presages a day of baking heat. It was early July, and the time of day conspired with the season of the year to produce an impression of almost uncanny perfection. The woods that threw out their flanking battalions towards the stream were heavy with consummated leafage; the hay standing in the fields glistened and steamed with the evaporations of yesterday; the larks sang in the unconscious egotism of their perpetual encore; the hedges were still fresh with the year's last revelation, the dog-rose; white wreaths of cloud sailed lazily across the distance, as if assured that they had no speaking part to-day. The cows stood whisking their tails gently, reserving themselves for greater efforts in the coming heat; rabbits sunned themselves among the hillocks, and scuttled away, stricken with imaginary fears; school-children dotted the lanes, their heads together in earnest debate over nothing; the air was full of promise and expectation; a wind blew, steady but with no chill, from the south-west.
And through this world of loveliness the river flowed, a secret world of its own. Lower down, the Thames mingles with the haunts and the activities of men; overgrown towns straggle along its borders, Maidenhead, Reading, Henley, Wallingford, Abingdon. But here, in these upper waters, it is divorced from the companionship of human life; the villages stand to one side and let it pass, turning their backs on it contemptuously at half a mile's distance; nor is there any spot between Oxford and Lechlade at which a cluster of human habitations fringes the river's banks, and owes its conformation to the neighbourhood. Unexpectedly it glides at your feet, in the middle of smiling hayfields or at the corner of a country lane; it has a traffic and a life of its own. Cushioned upon its waters, in punt or canoe, you see nothing but high banks on each side, deep in willow-herb and loose-strife, in meadow-sweet and deadly nightshade; or a curtain of willows cuts off the landscape from you; or deep beds of reeds stand up like forests between you and the sky-horizon, to meet haymakers in a field, to pass under one of the rare, purposeless iron bridges, makes you feel as if you had intersected an altogether different plane of life. Your fellow-citizens are the fishermen, incorrigible optimists who line the banks at odd intervals; the encampments of boy scouts, mud-larking in the shallows or sunning themselves naked on the bank; your stages are the locks, your landscape the glassy surface and the tugging eddies of the stream.
And the river, by virtue of its isolation, has its own sanctuary of wild life. It recks nothing of the road, a few hundreds of yards distant, where schoolboys throw stones after rabbits and ransack the hedgerows for nests. Here, in this lucid interval between two continents of human noise and labour, reigns no fear of the intruder Man. Frail and occasional visitors, the river-craft do not interrupt the solitude; they become, themselves, a part of the landscape, and Nature accepts them, unconcerned. The heron leaves his lonely stance only at a minute's warning; the kingfisher flies at your approach without consternation, as if protected by natural mimicry against its background of blue sky; fishes plop out of the water almost within reach of your hand, a sudden explosion amidst the silence; water-hens bob to and fro on the surface, waiting till you are close by before they will show you their hydroplane and submarine tactics; the voles race you along the bank, or let your prows cut through their wake; the dragon-flies provide an aerial escort, and flutter temptingly in the van. You are initiated, for once, into the craft of Nature's freemasonry; the highway you are following is older than the Romans, and you are not reckoned with the profane.

... [Nigel] ... as one who must always be acting a part, had dressed up very carefully as a 'river-man'; 'the Jerome K. Jerome touch', he had explained, 'is what impresses the lock-keepers'.
... A passer-by in a solitary punt, shading his eyes as he watched the pair vanish downstream, might have been pardoned for wondering at the vision.
The blurred roar of a waterfall, and a bifurcation of the stream with a danger-notice on the right-hand branch, heralded the approach of a lock. Shipcote Lock is not a mere precaution against floods; it is also a short-cut. The channel that flows through it is dead straight for nearly a mile, and only at the end of this is it rejoined, after unnecessary windings, by the weir-stream.
* Lock and weir are both at the higher end of their respective channels, * [NOT!]
and behind them, to right of the one and left of the other, stretches a considerable island, the further part of which is woody and uncultivated. A narrow plank bridge, thrown across the weir itself, renders the island accessible from the right; you can pass over the other branch by way of the lock itself, or (when this is shut up at nights) by a light iron bridge that crosses the lock-stream about a hundred yards below. The lock-keeper's house stands to the left on the mainland; but of his garden the greater part covers the upper end of the island, jutting out like a wedge and washed by the river on both sides.
If any man has a distaste for the society of his fellows, and loves work out of doors, and running water and the companionship of flowers, who could wish him better than to end his days as a lock-keeper? Or rather, to live as a lock-keeper until he can no longer stoop to wind up the winches, or strain to open the reluctant gates. In these upper reaches, only pleasure-boats go by; and their brief season is limited by the uncertain whims of an English summer. For the rest, when he is not actually plying his trade of outwitting nature, the lock-keeper can give himself wholly, it seems, to gardening, assured from the first that his flowers will grow in ideal surroundings, neighboured by the pleasant wedding of water with stone. Shipcote Lock is among the most ambitious of these fairy gardens; its crowded beds of pinks and sweet william, stocks and nasturtium, snap-dragon and Noah's-nightcap, seem to rise out of the water's edge like a galleon of flowers, with crimson ramblers for its rigging. Man, you would say, has first done violence to Nature by dividing the stream, damming up one half and forcing the other into a stone collar; and then, adding insult to injury, he has out-dared with this profusion of blooms the paler glories of the river bank.

'Are you sure he went upstream?' objected Bredon.
'That pub at Millington Bridge stands well away from the river; they can't have seen him from there.'
'No, but there's a boat place at the bridge, and the man in charge there saw him going upstream. ...
Millington Bridge is not among those one-way-traffic concerns in which our thrifty forefathers delighted; there is room to pass a lorry on it; but, by a kind of false analogy, it has a sharp angle over each of its jutting piers in which the pedestrian may take refuge from the dangers and the mud-splashings of the road. It is easy to lean over the parapet at these points, not nearly so easy to stop doing it; the leisurely flow of the stream beneath laughs at the scruples which would forbid you to spend another five minutes in doing nothing ... another ten minutes ... another quarter of an hour, so as to make it a round number by the clock.
... there was nothing to be done but watch the stream below them ...
It was one of those evenings when the clouds that have ushered out the setting sun find relief (you would say) after the formalities of that majestic exit by chasing one another and playing leapfrog across the clear expanse of sky. The sky itself had passed from fiery gold to a silver gilt that faded into silver; and now the massed cloudscape that had hung, in islands and capes and continents, with bays and lagoons of fire between them, across the Western horizon, broke up into grotesque shapes which breasted the sky southwards — a lizard, a plane-tree upside-down, a watering-can, an old man waving a tankard. They moved along in procession, like the droll pantomime targets of the shooting-range at a country fair, cooling off as they did so from crimson to deep purple, from purple to slate-blue.
The river, in the fading light, had lost something of its companionableness, but had taken on an austerer charm; the patches of light on it were less dazzling but more solemn, the shadows had less of contrast but more of depth. A silence had fallen on Nature which made you instinctively talk in a low voice, as if the fairies were abroad. The willow-thicket that nestled under the extreme right arch of the bridge, below which they were standing, stirred, and whispered with the first presage of a breeze.

The Gudgeon Inn stands close by Eaton Bridge, with a pleasant though untidy stretch of grass sloping down to the river; at the end is a tiny quay to which a few boats are moored, at the back of it a verandah, where holiday guests can have their tea in wet weather without actually going indoors. On the whole, there are worse places ...
There was nothing for it but to sit here and philosophize ... Indeed, the slow swirl of the river at his feet invited to philosophy;
A large peacock edged suspiciously into view: Nigel picked up some fragments of bread, doped them with gin, and threw them at the bird in the hope that it would become interested. A drunk peacock would surely be an exquisite sight; to see it lose, at last, the shocked staidness of its demeanour.
A camping party on the other side of the stream, a little lower down, claimed his attention; two brawny young men appeared to be washing up dishes, and hanging clothes out to dry. Nigel speculated whether it would ever be possible to enjoy the kind of life in which you had to wash up your own dishes and feed on tinned salmon. There seemed to be people who did it for the love of the thing. Probably it was a compensation of some kind; you could explain anything as a compensation nowadays. ...
The Gudgeon Inn is the sort of institution that only exists for the sake of people who see life in inverted commas. Externally it is just like a thousand other inns; the creaking sign-board, the modest lintel-announcement of the licence, the perspective of doors and passages that greets you as you enter, show no promise of disillusionment. But once you are really inside, you know the difference. The dining-room has no muslin curtains, there is no bamboo firescreen; the tables are not covered with ash-trays and salt-cellars advertising beer and mineral waters; there is no vast, unwieldy sideboard heaped with unnecessary coffee-pots. The tables are of fumed oak, and the flower-vases on them are of modern crockery in a daring orange; the sideboard is real Elizabethan, and serves no purpose whatever, any more than the three large pewter plates which rest upon it, obviously straight from an old curiosity shop. There are no stuffed animals in glass cases, no sentimental pictures with explicit legends in the manner of the later nineteenth century; no strange sea-shells on the mantelpieces, no horse-hair sofas, no superannuated musical-boxes. The walls are very bare and beautifully whitewashed; a few warming-pans and some mezzotints are all their ornament; there are open fire-places with brightly polished dogs, tiled floors, rush mats, wooden coal-scuttles with archaic mottoes carved on them. In a word, the inn has been recently 'done up'.
'It isn't an inn, ... it's an old-world hostelry, and it irritates me. I believe they expected us to dress for dinner; there isn't any commercial room, only a place they call the Ingle Nook; I can't find a dart-board anywhere, or an antimacassar. Their idea of a beer-mug is a thing you stick up on a shelf and look at.'
'It's such a pity you've no taste ...
'Taste? Who wants taste in a country pub? You can get taste in your own drawing-room. A country pub ought to grow up anyhow; with grandfather clocks that really belonged to grandfathers, and a spotty piano all out of tune, and sham flowers and things. Don't you see that this kind of thing isn't natural?'

The Windrush joins the Thames at Newbridge. It appears in the book under its own name (though at times it is spoken of as if it were upstream of Shipcote Lock). However it is mentioned as a canoing trip local to someone staying at the Gudgeon [The Rose Revived]

.. they would forget their solicitudes, and spend an afternoon mud-larking on the Windrush. ...
If Thames banishes care by his easefulness, the tributary Windrush is an even more certain remedy; that tempestuous rush over the shallows, those sudden windings, those perils of overhanging trees, demand entire concentration if you are to make headway against the unruly stream.
An afternoon spent on the Thames is spent with an old, tried, mature companion, who refreshes you even by his silence; an afternoon on the Windrush is like an afternoon spent with a restless, inquisitive child; you find in perpetual distraction the source of repose.
Both Miles and Angela had been stung with nettles, scratched with brambles, tormented by thistles underfoot, lashed with willow-branches, wetted by sudden inundations, tired out by ceaseless paddling, punting, and towing, before they returned to the Gudgeon;