Claudia and Steve get an intruder alert, which leads them to the shocking reveal that Paracelsus is alive and in the Warehouse. Meanwhile, Artie takes Pete and Myka to Buffalo to hunt down artefacts stolen from Warehouse 12 by Roaring Dan Seavey and his pirates centuries ago. There they find and team up with the duplicitous Charlotte Dupres whose agenda puts all their lives in danger.

The team continues their attempt to capture Paracelsus before he achieves immortality. Myka seems to be losing her battle with cancer. Steve learns that Artie has been hiding life-changing information from the rest of the team.

The agents capture Paracelsus, but soon discover that's exactly what he wants. Meanwhile, Myka goes in for surgery and Artie tells Claudia a family secret.