As the plague doctor furiously wiped away the muck, Rose tried the fifth and final key. The padlock clicked open at last and Rose flung back the top bar that imprisoned Jack.

‘Free Yori!’ ordered Jack, as he let loose a side kick that sent the sword-wielding plague doctor tumbling backwards into the mud.

Rose rushed over to Yori. But one of the other plague doctors had drawn a knife from the folds of his cloak and was intent on slitting Yori’s throat. Unable to run or evade the slash of the blade, Yori roared, ‘KIAI!’

The force of the shout stunned the plague doctor. The knife fell from his grasp and he dropped to his knees in a puddle, clasping his chest in pain.

Hurriedly, Rose inserted a key into the stocks’ padlock and got lucky first time. Yori shook the blood back into his little legs and leapt to his feet.

Jack ran over to his friends just as the two remaining plague doctors began closing in on them. One wielded a chain with pointed weights at each end; the other brandished a straight-edged sword with a distinctive square handguard. They were quickly joined by the other two, both now recovered but more wary of their foe.

Jack raised his fists in defence.

‘We don’t stand a chance!’ hissed Rose, glancing nervously from Jack’s bare hands to the array of deadly weapons confronting them. ‘We’re outnumbered – and out-weaponed!’

Yori started hyperventilating, in panic and in preparation for another kiai strike.

‘The bailiff has our weapons,’ Jack growled, as the plague doctors slowly began to encircle them.

‘Then follow me!’ said Rose, backing away. ‘I know where he lives.’

‘We can’t leave Akiko,’ insisted Jack, holding his ground. He felt an insistent tug on his arm.

‘What cannot be saved can be remembered,’ Yori said solemnly, retreating with Rose.

Jack shot one last longing look in Akiko’s direction – her slumped body a shadow in the rain – then took off after Yori and Rose, barely a second before the lead plague doctor lunged with his sword.

As the three of them fled the market square, their attackers gave chase. By now, the town was on full alert: the chief constable was barking orders and rallying his men, people were spilling on to the streets, alarmed by all the commotion. When they saw Jack, Yori and Rose sprinting across the square, their immediate thought was that they were escaped prisoners. Then the four plague doctors materialized out of the darkness and pandemonium broke out.

‘PLAGUE!’ yelled a man in horror.

Several people screamed and mothers gathered up their children and bundled them back inside, bolting their doors behind them. Townsfolk ran in all directions, desperate to avoid contact with anyone else. The chief constable tried to maintain order, but he was fighting a losing battle.