Jack reached the masthead. Although the Chinese junk sail worked in reverse to the square-rigged Alexandria – the canvas being raised rather than lowered – he immediately spotted the problem. The halyard block was damaged, its sheave cracked. In the Wind Demons’ rush to raise the mainsail, the halyard had slipped off the broken sheave and jammed.

‘Give me some slack,’ Jack called down, securing the rope on a cleat to hold the sail in place. With great difficulty, he worked the halyard free and realigned it. Releasing the cleat, he then instructed the Wind Demons to unfurl the sail slowly. Inch by inch, the sail’s yard spar rose up the mast. At the same time, the Sea Samurai on the other vessels were raising their sails and dropping their oars, determined to give chase.

From his vantage point, Jack could see across the entire harbour. The first seki-bune had left the jetty to block their escape. But, with its rudder sabotaged, the ship had no steerage and it ploughed straight into the harbour wall. As they passed one of the immense atake-bune, it made no attempt to pursue them. The holes drilled in its hull by Captain Hebi’s men had done their job and the ship was sinking fast. But, instead of abandoning ship, the quick-thinking samurai captain ordered his men to open fire. Cannon and musket shot strafed the shuinsen’s deck. Wind Demons dived for cover as the red bamboo guardrails and bulwarks exploded in a shower of splinters and iron shot. Even Jack had to shelter behind the mast as a number of arrows and bullets whistled past his head. Below, the screams of wounded ninja pirates pierced the night. But Skullface ordered no retaliating fire. Faced with an entire garrison, as well as the Sea Samurai force, their only hope lay in escaping the confines of the harbour. They were ahead of the surviving Sea Samurai ships, but they still had to sail past the castle and its formidable bank of cannon.

‘Back to your stations!’ commanded Skullface. ‘They won’t dare sink a Red Seal ship.’

But Skullface was wrong.

Lanterns burnt inside the castle, and through the loopholes Jack could make out silhouettes working furiously to load the cannon. It would be touch-and-go if the shuinsen made it through in one piece.

As they reached the harbour entrance, a loud boom thundered from the castle’s direction. This first explosion was followed by the blast of several more cannon. Jack instinctively ducked, vainly shielding himself from the approaching iron shot.

But nothing hit the ship. Jack looked up to see the castle half in ruins where all the cannon had backfired.

‘WANIZAME!’ roared Skullface, brandishing his sword in triumph. The rest of the crew cheered in salute of their fellow ninja pirates, who’d accomplished their mission with devastating effect.