He gripped the man’s arm, smelling his fear. Now was the time to make the Spaniard more afraid of him than of anything the enemy could do. “Listen to me!” He shook the man slowly with each word. “When we are challenged, you know what to do?”

The Spaniard nodded violently. “Show lantern. Give the signal, excellency!”

“And if they ask why you are coming in at night tell them you have despatches for the garrison commander.”

“But, excellency! I never get despatches!”

“Hold your tongue! Just tell them! If I know anything about sentries, they’ll be satisfied for long enough!”

The pier crept out of the darkness like a black finger, and as the sails were lowered swiftly and the lugger glided gently towards the tall piles a lantern flickered into life and a voice yelled, “Qui va la?”

The Spaniard opened the shutter of his own lantern. Two long flashes and two short ones. In a quavering voice he began to stutter his message, his words broken up by great gulps for breath. He was shaking so badly that Farquhar had to hold him upright against the mast like a corpse.

The sentry called something to another man, as yet hidden by a small hut in the middle of the pier, and Bolitho heard him laugh. There was a click of metal and then another as the sentries uncocked their muskets.

The bow swung against the pier, and Bolitho saw the sentry leaning forward to watch the lugger bump alongside. He had slung his musket over his shoulder, and his tall shako shone briefly in the glow from a long clay pipe. Bolitho held his breath. This was the time to see if he had chosen his men correctly.

He saw a sailor, moving with elaborate calm, climb nimbly up the nearest wooden ladder, the mooring rope in his hand. The sentry called after him, his voice muffled as he turned his back to watch the man looping the rope’s eye over a bollard.

The next sailor, who had been crouching on the stem, leapt straight upwards like a cat. For a moment the two figures swayed together in a macabre dance, but there was hardly any sound. Only when the sailor released his grip and lowered the dead sentry carefully on the pier did Bolitho realise it was time to act.

He snapped, “Next man up!”

Belsey, the master’s mate, slipped over the bows, and followed by the other seaman who was wiping his knife blade on his trousers, disappeared around the side of the hut.

This time there was a little more noise. A clatter of a falling musket, and something like a gurgle. But nothing more.

Bolitho scrambled up to the pier, his body shaking with suppressed excitement. “Right, Mr Okes, get your party ashore and up to the end of the pier at the double!” He stopped an onrushing seaman with the back of his hand and snarled, “Quietly there! There’s a guardhouse at the far end!”