Trail of Blood

"" is the fourth episode of the third season of Sanctuary, and the thirtieth episode overall in the series.

Synopsis
The team travel to the mountains of Colombia to track a call for help from Nikola Tesla. Meanwhile, Bigfoot investigates the death of an old friend, and witnesses the arrival of a new enemy.

Cold Open
Dr. Will Zimmerman and Bigfoot are in the process of discussing the pros and cons of having fish for breakfast, when suddenly Bigfoot hears a strange noise that leads them to the catacombs. They find a strange device that looks like a very old typewriter and seems to operate on its own. They take it to Dr. Helen Magnus, who explains it is an autotype, the last of five such secret communication devices used by the Allies during World War II.

Will asks who the message, which states simply SOS, can be coming from if this is the last surviving autotype. Magnus explains that the distress call must be coming from the machine's inventor: Nikola Tesla.

Act I
Henry is able to pinpoint the location of the signal's origin in the Colombian Highlands, 300 km west of Cartagena. Magnus decides to go and find Tesla, a move Will is less than enthusiastic about. Bigfoot and Kate Freelander decide to spend the free time watching "Operation Paranormal", a mystery-themed investigative show, on DVD. After they fall asleep for a while, a news reporter reports the death of a priest, Father Nathaniel Jensen, during a burglary at his church. Visibly distraught, Bigfoot gets up and leaves.

In the mountains of Colombia, Magnus, Will, and Henry climb into a cave and start looking for Tesla. They soon discover strange large filamentous substance, hanging down like long white roots everywhere, they cannot identify. Magnus states they're hollow, somewhat vein like, in structure.

At the crime scene in the Fifth Ward, Bigfoot's memory drifts back to 1951, when he was injured and found by Father Jensen. The priest took care of him, and directed him to the Sanctuary. Kate arrives, and Bigfoot explains that the priest was a good man, and a friend. When one of the policemen announces that they have a suspect on the run, a look of grim determination appears on the abnormal's face.

In the caves, the team finds Nikola Tesla trapped in said strange substance. He informs them that it is made by creatures who are "far from pleasant". They cut him free after some difficulty, but are attacked by a number of small, insect-centipede-like creatures who come crawling in from all sides.

Act II
The team retreats with Tesla and blocks the way behind them. Magnus inquires what Tesla was doing in the cave, but he gives no answer. In the end, the team is able to find out he is there for the magnetic metals in the rock, which he hopes could help him control or emphasize his magnetic powers, or 'something'... .

In Old City, small-time crook Denny Stefano is running from the police when he is suddenly caught by Bigfoot, who angrily accuses him of killing Father Jensen. Stephano tells him he's innocent, and after smelling him, Bigfoot seems unsure, too. He decides to take the young man with him.

In the cave, the team discovers what turns out to be an unmarked bunker and the actual reason for Tesla's presence. The centipede creatures reappear, and Tesla seals himself and the team inside the bunker. He then explains that the facility is a secret Cabal laboratory.

Act III
Magnus concludes that the creatures are actually the result of Cabal experiments gone awry. Henry and Tesla soon start working on restoring the lab's database.

Back in Old City, Bigfoot and Kate conclude that Denny Stephano is being set up. Kate suspects that a member of the police is the true killer. Bigfoot remembers that Stanley O'Farrow, the officer in charge of the investigation, acted strangely at the crime scene. Suspecting him to be an abnormal, they decide to "bring him in".

Henry and Tesla have found a way to hack into the lab database, and the team soon discovers that the lab contains a sample of the source blood, the original vampire blood that created and turned Ashley Magnus into a monster. They also discover that the lab is the location of the insect/centipede creatures' nest. They realize that the abnormal creatures were created when the bunker self destructed and spread Source blood throughout the caverns infusing them with it in the process, hence their magnified size.

Act IV
The team considers ways to destroy the creatures, while Tesla wants them to give him time to do the necessary research to recreate the source blood. Magnus angrily refuses, and orders her team to blow the nest up - and Tesla along with it, if he refuses.

Meanwhile, Kate and Bigfoot have prepared a trap for Officer O'Farrell, using Denny as bait. Once he arrives at the scene after following their anonymous tip, he points his gun at the young man. Denny offers no resistance, but O'Farrell does not seem to be fully in control of himself. Just before he can pull the trigger, Bigfoot overwhelms him and brutally slams him into a wall. He demands to know why O'Farrell killed the priest. The policeman says he had no choice, and that "he" got everything he wanted. At that point, a hooded figure briefly appears on a roof behind Kate and Denny, and then O'Farrell suddenly dies.

In Colombia, the team is ready to blow up the nest. Tesla opens the door, allowing the creatures to enter their nesting grounds. However, they soon go after Magnus, whose body also contains source blood.

Act V
In order to save the others, Tesla cuts himself, leaving a trail of blood for the creatures to come after. He then locks himself inside the lab moments before it is blown up. After the explosion, the team finds Tesla almost unhurt, as he used his abilities to surround himself with metal for protection. Magnus and Will both realize he likely took one of the larvae, but decide to "leave him his moment".

Bigfoot is alone on a roof when a young priest, Father Clark, approaches him and tells him that Father Jensen told him a lot about the abnormals of Old City. Bigfoot explains that the Father was like a brother to him. Father Clark tells him that he hopes they will soon speak again.

Magnus later tells Bigfoot that O'Farrell died of a brain aneurysm, and that his family had been held prisoner by someone who later gave an anonymous tip where they could be found. Bigfoot realizes someone forced the policeman's hand, but he can only wonder who it was.

In an empty street, Father Clark removes his clerical collar and glasses, and throws them into the garbage. He then pulls the hood of his coat over his head, revealing himself as the hooded figure Officer O'Farrell saw, and walks away with a smile.