The Wraith is a masked Londoner with three murders to his name. He likes theatre, he's quite theatrical and has always been a step ahead of Scotland Yard. This is the closest you've been to him no more than 10 yards away as you sprint through the dark warehouse. You leap up over the hidden trip wire that the Wraith jumped over when he threw the firecracker. The other detectives cautiously climb around the sharp spikes. Deduction success.