Vanishing thieves

Book 64 here in the UK. A nice tale about the boys going to L.A. to track down a 1913 Liberty Head nickel once owned by Chet Morton's Uncle. The Vanishing thieves part comes from a sub plot where a car theft ring is stripping cars down for parts and Chet's Cousin Vern has his car stolen. A few times they try to catch them at it but in all cases the gang disappear and set up shop elsewhere. And finally seeing as Joe Hardy is tipped overboard by the thugs and is rescued from a shark attack by a pod of dolphins, this is officially where the series jumps the shark*. A good tale with a good balance between numismatics and car theft and its not often you can say that. You can read the original here and the UK version here there is no difference between the two sadly. *The actual place where the series jumped the shark is The Stone Idol a nothing burger of a case where the boys travel to Antarctica for reasons.