This episode follows a similar outline to the season 5 episode "The Next Phase" - a small group of Enterprise officers encounters a weird scifi phenomenon triggered by a Romulan ship calling for aid. Overall, this is a better episode - particularly because it's a more interesting concept, but also because the small ensemble is stronger - not just Patrick Stewart and Brent Spiner, but also Marina Sirtis in one of her best acting jobs on the show. There's also a nice air of mystery that surrounds the episode - what the hell is going on, and how will this disastrous situation be resolved?
The biggest drag is the underlying concept. Were those weird aliens really necessary? They just seem grafted on pointlessly and the story would have worked better without them.