When a Section 31 spy is revealed, T'Lorra takes matters into her own hands. Meanwhile, the Odyssey comes face to face with an Archein ship intent on their destruction.
The crew finds a dead planet once populated by Archein scientists. However, once the preserved body of one the scientists is discovered, so too is a conspiracy that pushes Stadi to her limit.
Ro is once again confronted by the prospect of losing a member of his crew. In order to stop this, Ro must undergo a spiritual journey which leads him to the true identity of the mysterious Great Ones.