Contains spoilers from The Flash Season 5, Episode 6.
Since returning for its fifth season, The Flash has brought a number of new storylines to the forefront. From familial issues to new Big Bad, Cicada, almost all of these new arcs have one thing in common - they stem from the arrival of Nora West-Allen.
Aside from that, there is one storyline that has nothing to do with Nora's time-travelling antics and is, in fact, directly related to the events of last season - that is Caitlin's quest to track down her father, Thomas Snow, and re-awaken Killer Frost. After bubbling away under the surface as the show's secondary arc, it finally received some much-needed attention in this week's outing, 'The Icicle Cometh'.
The episode saw Caitlin, Barry and Cisco travel to an unused Tannhauser facility to discover that Thomas was indeed alive after all this time. However, he wasn't the only person she reconnected with, and given that not everything was as it seemed, that's a darn good thing.
All in all, this instalment showcased one of the season's lesser-appreciated arcs without taking a significant break from the main narrative. Though it wasn't all perfect, it did a great job of progressing things on every front. Contains spoilers.