Episode 60 S04E10-11 Waves/End of a Line

Ordinarily, I'd be all over a tale about mermaids, but the only redeeming grace here is that the story brings Lauren, Dyson and Kenzi closer together as Bo shuts them out to be with Rainer. Arguably, the most poignant scene in the entire series occurs as Kenzi's heart is shattered when the love of her life dies, due in part to her own hubris.