Although that specific episode, "Silent Enemy," has one of the eeriest and most effective alien species in Trek history, a species with a bizarre design and appearance that speaks no words, simply boards the ship to poke around Enterprise's systems and then flies off into the void, never to reappear. Malcolm's birthday cake subplot doesn't bother me but it also does little for me.
It’s one of my favorite early Enterprise episodes despite the Malcolm/Hoshi subplot.