The Birthday Trap - S1.E10

Robin goes to the fiftieth birthday party of his step-mother, where he encounters an old girlfriend. But a band of thieves enter the castle and interrupt the festivities. They round up the guests and steal all their money and trinkets. Robin is seriously wounded in the battle to recover the stolen items. Knowing the castle well, he relies on his cunning to separate the thieves, and lay traps for them in the rooms they find themselves locked in. But Robin faces his biggest battle high on the castle walls.