Invasion:The Journey of Allen Strange #2:Nickelodeon (Journey of Allen Strange)

Nothing's the same for Robbie and Josh Stevenson with Allen Strange around, not even a trip to the Natural History Museum. The alien-turned-human is delighted with the exhibits showing the early days of his host planet -- until he recognizes the fabulous Mojave Diamond as an ancient Arubii signaling device. If it is activated, the diamond will call the insect-like aliens to colonize Earth and destroy human life. The device seems to be broken, but Allen protects it with a Xelan alarm to be safe. But Allen's alarm can't stop a burglar from stealing the diamond and accidentally activating the signal for the Arubii to land. Allen, Robbie, and Josh have only two hours to find and deactivate the diamond before the enemy aliens invade. It's a race against time to save the planet -- and keep Allen's secret safe!