Lemmy comes back from Mars along with a Space Squid, who is mysteriously stealing objects from the zoo to communicate with its planet, and paralyzing the zoosters.
When Lemmy (LEM-R) (last seen in Lemur See, Lemur Do) crash lands in the lemur habitat, he tries to warn the penguins and lemurs that they're all in danger, but a baby Space Squid tears through his chest, seemingly killing the robot, much to Kowalski's horror. The squid runs off, taking Julien's boom box before the Penguins can do anything, but not before temporarily paralyzing Mort (who retains the ability of speech which Kowalski noted). While observing Mort's current state and Lemmy's self-repair process, the space squid's tentacle bursts into the Penguin habitat, grabbing their Speak and Spell. The penguins try to grab it but are shocked to find that the squid has matured quickly and is now so large that only its tentacles can fit inside the habitat.
The penguins split into teams (with Skipper trying to pair up with Lemmy's head, but unfortunately for him, Julien tags along). Skipper's team observes the space squid stealing several different items around the zoo while Private and Maurice try to find the squid so they can offer friendship bracelets (they instead offer one to Marlene to apologize for breaking into her habitat). Rico and Kowalski investigate around the zoo habitats.
Eventually, they confront the space squid who is using all the collected items to send a message through space in order to commence an invasion. Private though, still naively thinks he might be friendly and not hostile. Suddenly, the squid paralyzes him. Now fully realizing that any attempt of peaceful negotiations with the Space Squid are all but impossible, Private gives up playing devil's advocate with the squid and yells for his team to kill it. The Penguins and Lemurs try to fight the squid, but all end up paralyzed with only Skipper, Julien and Lemmy's still-severed head. Just when Skipper and Julien are paralyzed (in a rather awkward position), Lemmy returns, fully-repaired, and attacks and defeats the space squid with an assortment of Penguin fighting moves and Lemur dance steps. Lemmy then drags the space squid back into outer space. Julien asks if they will ever see him again. Skipper says they will, after Lemmy teaches those aliens a lesson.
As to their current predicament, Kowalski predicts they may have a week or two till the paralysis wears off. Thus, the penguins and lemurs start hopping off to their habitats. Private then stumbles.