Mrs. Brown's purse is stolen at a carnival. Det. Brennan automatically suspects Raymond, a gypsy, only because the detective thinks all gypsies are crooked. Martin knows Raymond didn't do it. But because the detective hauls Raymond off to jail, Raymond places a curse on Mrs. Brown. For her, the curse is a self-fulfilling prophecy. Martin thinks that he can help Mrs. Brown get over the thought of the curse - that everything will slip through her fingers - by becoming invisible and holding onto things for her. Unfortunately, Martin's antenna are temporarily malfunctioning, so he can't disappear. The only other option is to have the curse lifted. Raymond won't do that since the detective won't release him from jail. In fact, he places the same curse on the detective, who scoffs and laughs at the curse on him. Brennan is on a spree of rounding up all gypsies for a recent spate of crimes. This doesn't bode well for Martin, who's next plan is to go undercover as a gypsy and remove the curse from Mrs. Brown. Just before he can do so, Brennan arrests him. Just as Brennan is about to book all the gypsies down at the police station, Martin announces that he has lifted the curse from Mrs. Brown and has placed a curse on the detective. Just hearing that cures Mrs. Brown. However, Martin requires a little Martian trickery to enact the curse on Brennan. Unlike Mrs. Brown, Brennan, a metaphysics junkie, really does believe he has a curse and is happy about it, as he can be observed as a scientific marvel. And the real thief of Mrs. Brown's purse is apprehended and is not a gypsy.
—Huggo