"Nightfall" perfectly illustrates why Terra Nova's choice to be all things to everybody — by attempting to deliver a fast-paced action show centered on a family — is slowing down the story and is starting to affect the overall quality of the show. The earlier episode "What Remains" worked because there was one prominent family story that happened to be interesting. Unfortunately for this episode, having multiple such storylines (of equal importance) backfired, as none of them really shined.
"Nightfall" started with one of those details that makes the viewer appreciate the irony of the situation. The sight of the two meteors zipping through the atmosphere had to conjure up thoughts of the Cretaceous extinction that marked the end of the reign of dinosaurs. We know the settlement is in a different timeline, but the odds of a large meteor impact are as significant as in the 2149 timeline around the same geologic period. The introduction of sonic waves and an EMP (however unlikely they may be) was a nifty and spectacular way to get to the different situations developed throughout the episode.
Mira coming after the box made sense, but there were a few questionable things about the storyline. Boylan, the bar owner, running to the science department bungalow and shooting the Sixer fighting with Taylor is one of those events designed to surprise. I find it better when a cliffhanger is designed to make us wonder what will happen next and not what the motivations of a character have morphed into. The latter feels like cheating, like changing a character to fit the story. Also, I don't generally mind when protagonists are written as "chosen-ones," but Taylor has a small army under his command, so seeing him and Shannon systematically out front in every battle has become annoying. Finally, Taylor's son Lucas letting us know that the Sixers came to Terra Nova to recover the box (and nothing else?) before disappearing doesn't really move the story forward significantly. We already knew the Sixers had an agenda connected to the "real" goal of the settlement (whatever that may be) and that Taylor's son was involved, so this is just another instance of the show lingering.
If a thirty-foot parasite is being taken out of your tummy by a charming young woman who should follow a careful procedure, it might not be the best time to let her know you have been pining for her. The best thing about this situation was Elisabeth, and to a lesser degree getting Elisabeth and Skye to work together, which led to the invitation to dinner. After seven episodes, Shelley Conn, who plays Elisabeth, is the only cast member who hasn't had an uneven performance and whose character hasn't been misused.
Maddy's escapade, besides as being reckless as any such foray out of the gates, was not as romantic as the show would have liked it to have been. The chemistry that is palpable between Josh and Skye is not flowing around Maddy and her soldier. To make matters worse, it was a bit odd for him to promise he would not let anything happen to her while the only course of action they had was to run. The best thing about this storyline was the interaction between Maddy and her family, particularly her brother, before and after her date.
Although the Eye was enchanting for Zoe, and she was appropriately sweet throughout the episode, the story of how she came into the world wasn't told well enough to make us truly exonerate Jim Shannon, a cop who could have really avoided having a third child in 2149. It is interesting that the show is voicing that explanation through Jim, which in a twisted way would seem to confirm that the recklessness of that pregnancy is something we should associate with him and not with his wife. Zoe's logic was priceless: there was no spider because the spider-repellent song worked.
"Nightfall" was a much more decent episode than the previous one. It showcased an attempt to advance the main storyline, at times displaying the series' potential, but was also mired by clumsy love stories, an ineffectual excuse for a thoughtless decision and a failed attempt to spike our curiosity.