Helix

Peter Farragut, Sarah Jordan and Dr. Kyle Sommer go to a mysterious island to investigate an unknown pathogen that killed everyone, except Leila, aboard the Mist of Avalon.

Jordan discovers Alan, Peter's brother, is a member of Brother Michael's cult, but despite Alan's warnings she and Peter refuse to leave the Abbey and continue to investigate how Soren became infected.

Peter and Jordan leave the safety of the Abbey to retrieve some specimens and discover just what's living in the woods, meanwhile Sister Amy plots to make them leave forever.

Michael struggles to keep the abbey under control as the CDC team move closer toward tracking the source of the pathogen; at the same time, Alan fights the urge to rejoin his former colleagues and comes to terms with the reality about Peter's allegiances. In the future, Walker takes a risk attempting to escape her delusional father.

Peter reveals his brother's secret and gets them both in trouble, meanwhile Kyle has his hands full trying to quarantine the orchard and the infected hive.

The CDC team are forced to work together when another outbreak threatens to overwhelm the Abbey

Things go from bad to worse on the island. Elsewhere, Walker decides to go to St. Germain after learning about Brother Michael.

The Coast Guard arrives on the island to take the CDC team to another island to deal with another outbreak of the pathogen, meanwhile Sister Amy has to contend with Brother Michael and his plans.

Walker and Balleseros arrive at the Abbey while Alan, Kyle and Winger are out in the woods searching for the tree with red sap that might be a cure for the pathogen.

At the Abbey Sister Amy makes a bargain for immortality, while in the woods the race is on to find the Bleeding Tree now that Kyle is infected.

Walker prepares to implant Jordan's baby into Amy while the Navy prepares to implement Plan B, a final solution to ensure the virus and all infected people never leave the island.

While Kyle and Jordan try to escape the island as the followers hunt them, Walker and Alan search for the Mother Tree so that Walker can halt ILARIA's deadly plan.

In the Season 2 finale, Alan's relationship with Walker reaches a bloody climax, while his sibling feud with Peter erupts in flames. Elsewhere, Kyle does his best to protect a possible cure for the mycosis.