S1, E6: For her birthday, Mertle gets a bracelet... with an unactivated experiment pod attached to it! Lilo notices the experiment pod and realizes she must get that bracelet from Mertle. Soon she and Stitch are practically stalking Mertle, but are constantly being foiled by a local police officer. Stitch finally is able to discern the number on the pod: Experiment 606, a black hole experiment that will suck in the whole world!