As the gang prepare for Faraz and Gillian's wedding, Faraz mysteriously vanishes and it's down to Taylor, Nori and Ellis to find him while Meesha and Lila try desperately to keep the wedding on track.

While staking out Raquel at Rock Island Dam, the gang are visited by two versions of Uncle Charlie - one younger and one older. They team up to investigate what Raquel is up to, but soon discover that they're all in serious danger.

It's the launch day for the Institute's new submersible and Ellis is keen to show off his hard work. But when faulty programming accidentally launches the sub into the ocean, Taylor, Ellis and Meesha are trapped below the depths.