While Mal and Jake are busy chasing after a hit man, Martin Poole returns to make Rose's life difficult. Tinny makes a decision regarding what path her life will take.
Jake arrives back in St. John's from his mysterious boat ride, only to find that he's in a worse situation than when he left. Tinny goes too far, and someone new to St. John's is showing interest in Leslie.
Holder looks to make someone responsible when the hunt for the pornographer unearths a shocking revelation. Lyric and Twitch discover the home of their dreams.
The Masons are in for trouble when Hal 's intentions come to the surface.
As Bullet wrestles with the truth, Sarah and Holder talk to the latest victim. Seward is confronted with his past.
Another alien attack is thwarted resulting in a meeting between Tom and a powerful leader.
Sarah and Holder, aided by Bullet, desperately search for a victim on the run. A surprise visitor brings out the worst in Seward.
While the task force shuts down a business, Linden and Holder unite as they pursue "the voice" from the video. Seward becomes motivated to obey orders.
The mole is still at the front of everyone's minds, especially when they come under sniper fire from a young girl. Anne continues to worry about her baby.
Linden is determined to join the task force for her own reasons while Holder discovers a new street informant. Seward strokes an old rivalry.
Arthur Manchester investigates a mole in the ranks, and the Volm seek assistance in destroying a power source for Espheni weapons.
In the Season 2 finale, the skitters draw closer to the consolidated resistance force. Elsewhere, the 2nd Mass come across their biggest threat as Tom discovers game-changing information.
Cullen must deal with his transgressions and Elam isn't happy about his decision. With Lily now a major force in the design of the railroad, she and Durant push the railroad west.
Tector makes the decision to embrace his military past, while Maggie becomes suspicious that Pope will be leaving he group. The 2nd Mass continue to meet new people along the way, as Tom runs into a former untrustworthy mentor.moreless
The 2nd Mass finally make it to Charleston but is there anybody there for them to join up with?moreless
Tom lands himself another captive andBen is lead into danger at the hand of someone he trusts. The unit faces a brand new enemy while trapped in the basement of a building.
While on patrol, Hal and Maggie discover an unharnessed and alive Karen among a group of half-buried unharnessed corpses. Tom has some tough decisions to make when Weaver falls gravely ill from the bite he received at the harnessing factory.moreless
A skitter is captured and imprisoned at the camp, Hal bonds with Maggie as they discuss her past, and a familiar figure returns to the group with questionable motives.
Hal and Ben have their bikes stolen while out on patrol and the hunt to retrieve them leads to the discovery of something much bigger. Matt finds himself in serious danger and Weaver rediscovers a lost family member.moreless
The 2nd Mass moves into an airport hangar but the situation gives Anne reason to worry about the health of the group. Meanwhile Pope and The Berserkers hatch a plan to deal with Tom. The group suffers a great loss but receives a promise of hope from a mysterious visitor.
Tom begins to wonder if his mind was affected during his captivity whiles truggling with the memories of what happened while he was with the aliens. While trying to find a way to escape the approaching Mechs and Skitters the 2nd Mass comes across a bridge that could lead them to safety, when the bridge is damaged it's up to Ben to scout the area for signs of the enemy while Jamil attempts to repair the bridge to allow the convoy to cross. Ben makes a discovery and along with Hal, Dai and Karen must launch an attack to protect the rest of the group.moreless
As SCIU threatens the nascent Abnormal "Homeland" (with a deadly weapon partly designed by Nikola Tesla), both Magnus and Caleb come under "friendly" fire. Cornered and determined, Magnus responds with a daring move no one - on either side - sees coming.moreless
Magnus is asked to help broker a peace agreement between Caleb, a Hollow Earth insurgent leader, and the world's governments - an agreement whereby Abnormals would be permitted to settle on the surface. Preparing to take military action against the Abnormal forces, Addison "drafts" Will back into the federal government, further dividing Team Sanctuary.moreless
Seeking to outrace the SCIU (who are attempting to capture a rare, legendary Abnormal), Magnus and Will are captured, injured and trapped in a Bolivian cave-in. Alone, the two friends struggle to survive - as they confront who they are and who they've become.moreless
Kate returns from Hollow Earth with word that insurgents are about to strike an above-ground target - and may have inside help from a trusted member of Team Sanctuary.
Just when Magnus thought Adam Worth was gone forever, she and Tesla become trapped in a virtual Sanctuary, where they are attacked by an avatar of Worth - who is determined to enter the "real" world.moreless
When a previously unknown Abnormal attacks Abby, Magnus and Will attempt to communicate with the creature using music - while Henry and Gavin retrace Abby's steps to find out what happened.
Team Sanctuary investigates a mystery on the high seas when the shipwrecked crew of a Bering Sea icebreaker murders the Abnormals on board and then turns on each other.
While Magnus deals with two ne'er-do-well flying Abnormals who entangle her in a wild scheme, Will takes a road trip to Monrovia - where he is unsettled by personal revelations and temporarily blinded during a riot.moreless
Magnus and Henry attempt to infiltrate a secret Abnormal testing facility run by Homeland Security and encounter an old friend whose loyalties are once again in question - Nikola Tesla.