“In Too Deep” is episode eight of season five of Eureka.
Following the events of the previous episode, “Ex Machina”, Holly has been rescued – sort of – and is now living in S.A.R.A.H. – the computer, not the house itself. Which means, as well as Allison and her kids, Carter also has S.A.R.A.H.’s boyfriend, deputy Andy, and Holly’s boyfriend, Fargo, all living in his house. Admittedly, Fargo converted the bunker in the first place, but it’s getting a bit crowded.
It’s also Feynman Day (celebrating Richard Feynman) at Global Dynamics, and everyone is playing pranks. Well, except Jo. Carter surprises Allison by taking her on a romantic cruise in the new mobile lab, but things don’t go to plan. Allison is worried about their relationship, and the virtual one Carter had with Jo, and Carter is worried he’s simply not smart enough for her.
Then the cruise goes really wrong, as the submersible crashes to the bottom of Eureka’s, incredibly deep, lake. Giving them limited oxygen and a submersible that isn’t designed for such depths.