Here's a look at tonight's sci-fi TV:
Lost, 'Across the Sea' – Our favorite castaways take a backseat as tonight's episode focuses on the very long struggle between Jacob and the "Man in Black." Word is that the flashback-heavy story will reveal the Locke-ness Monster's true motives and, hopefully, will help bring the series' end game into focus. West Wing vet Allison Janney guest stars. (9 p.m. ET on ABC)
V,' 'Fruition' – Erica finally comes face-to-face with Anna, and the V's threaten to leave Earth right as a scientists claims to have developed a weapon to fight them. (10 p.m. ET on ABC)
Head after the jump for preview clips and more TV picks.