This episode was an interesting concept, the gang targeting Keira's grandmother. But I don't know, there was in the execution that just didn't sit right.
We have a Terminator-style plot (which is actually lampshaded in the episode) in which the gang is targeting everyone named "Lily Jones" knowing this to be the name of Keira's grandmother and hoping they can erase her existence. Kiera wonders how it's possible they can know who her grandmother is despite the fact that she knows about the ancestry of all of them. The gang learns Kellog is working against them so they kidnap his grandmother, to blackmail him into delivering Keira's grandmother. Kiera instead blackmails the gang by going after Bra'tac's mother, while she's pregnant with him. When all is said and done, Kellog's grandmother ends up killed, but since he still exists this just raises more questions.
Meanwhile Bra'tac is imposing a new plan with the gang, an actual plan as opposed to mindlessly rampaging around killing people. This doesn't sit well with Roger Cross and Lexa Doig. During these scenes I keep thinking of Wash playing with dinosaur toys in Frefly's pilot episode saying "curse your sudden but inevitable betrayal."
My main problem with this episode is that it dragged on. It felt like it had padded out, particularly with two drawn-out musical montages. They had a good idea, targeting each other's ancestors, but it ultimately resulted in a shoot-out in which everyone's mother or grandmother is targeted and one is killed with no apparent impact on the one descended from her.