Elinor is fascinated by the strap on Ari’s cool new watch. It makes a skrrrrtch sound when he opens it, and then he can just press it closed again. “The two parts stick together like tape, but they aren’t sticky!” Elinor says. How does it work? She just has to figure it out! With the help of Ari and Olive, Elinor decides to investigate which other things the material on the watch strap sticks to - the rug, a sweater - and which it doesn’t - everything else, it seems. Then, while they’re searching outside, some spiky seeds get stuck on Ari’s sweater. Elinor discovers they make the same sound as the watch strap when she pulls them off. Could the seeds be a clue to unraveling the mystery?