Plot hole: Skipper spots the Masked Mutant's headquarters the first time he goes past. He then goes back the next day, and the headquarters have vanished. He then goes back a third time, and the headquarters aren't there yet again. However Skipper says "How can it be. It was right here yesterday," although it wasn't.
Continuity mistake: Just before Jessica goes and asks the woman with the pram if she'd like some lemonade, we see Nicki put the plastic cups down beside the 'Cash' box. In the next shot of Jessica talking to the woman, the cups are on the other side of the table. They're back in their original place in the next shot.