ON THE RIVER BOAT Dusk was falling on the broad river, and the bold ridge behind the city stood out sharp and black against a fading gleam in the western sky.

A big, sidewheel steamer, spotlessly white, with tiers of decks that towered above the sheds and blazed with light, was receiving the last of her passengers and preparing to cast off from her moorings.

Richard Blake hurried along the wharf and, on reaching the gangplank, stood aside to let an elderly lady pass.

She was followed by her maid and a girl whose face he could not see.

It was a few minutes after the sailing time, and as the lady stepped on board a rope fell with a splash.