“Trail of Blood” is episode four of season three of Sanctuary.
Will and Bigfoot are arguing over the latter’s decision that salted cod makes an excellent breakfast food when Bigfoot hears something down in the catacombs. There is something underneath a cover, a mechanical device that is clicking and operating. Will and Bigfoot take the device to Magnus, who says it is an autotype, a device that transmits and receives messages that cannot be intercepted, one of five built during World War II and one which she convinced the inventor to give to the OSS. Now, this autotype is the last one remaining. With it being the last one, there is no other device capable of sending it a signal. Magnus says that the only person capable of doing so is the autotype’s inventor – Nikola Tesla. The message is an SOS and it’s coming from the Andes near Cartagena in rural Columbia. Magnus tells Will and Henry to prepare to travel there; Will says they cannot trust Tesla as he always has a hidden agenda – always.
In Columbia, the message location is underground in a cave system, one with an unusually high iron concentration – and some weird metallic strands of stuff, similar in some ways to hair. Tesla is encased in these strands, and has been for some time. He says he was trapped by a creature that lives down here and that they need to leave promptly.
Before they manage it, the creatures appear – very bug, as in several foot long, centipedes of some type that Magnus does not recognise. They manage to get away but have to collapse part of the ceiling, and are stuck underground. Tesla, who lost his vampiric abilities at the hands of his own devamper (as Kate pointed out, for a genius, that was a terrible name) in “Sleepers”, although he gained some magnetic powers as a result, and he came to the location looking to enhance them. This is not true, however, when, as they are looking for a way out, they stumble across a buried, and largely destroyed, bunker. This is what Tesla was actually looking for, a hidden underground lab belonging to the Cabal. The giant centipedes may be a result of the lab’s research, so they need to find a way out and get past the giant bugs.
Back in the Sanctuary, after Kate returns she and Bigfoot watch the latter’s guilty pleasure – the series Operation Paranormal – on the big screen in the media room. After falling asleep watching the program, Bigfoot wakes up during a news report saying the an elderly priest, Father Jepson, who worked in the Fifth District of Old Town with the homeless, has been murdered. Bigfoot heads out to the scene – back in 1951, a much younger Jepson found Bigfoot injured and took him to the Sanctuary.
The police have a suspect, a known criminal, and Bigfoot and Kate go looking for him. The suspect says that he is being framed – and Bigfoot believes him. But who is framing him and why? Possibly the actual murderer, so Kate and Bigfoot investigate. Which leads to what looks like a new player on the scene.