There’s a special day and it’s called April seventh. Yeah, yeah, the MM Mystery. The two girls sang that song while riding their bikes up and down the street, celebrating that they had a genuine mystery to chew over. The mystery was as follows: They tracked the Nanny, Mercedes, who was pushing the baby brother in a stroller. The date was April 7th. Can’t you just hear the tuba underscoring the sense of mystery, dread and doom? In their eyes, the Nanny was guilty, worthy of scrutiny, because she dyed her hair a different color every week or two. At the end of the next block, near the train tracks, the scarf Mercedes was wearing was gone. It wasn’t tucked into the front of the baby buggy. It had disappeared. To the girls it was obvious that the Mercedes was communicating with her partner, signaling that now was the perfect time to kidnap the baby brother. Nothing ever did happen. But that moment, that little blip kept them going until August.