Okay, here's what they did . . .
Ace betters Black Jack as Ace goes after the strontium and Jack changes back into his debilitating condition. Ace recovers the strongbox and makes it back to the surface after spending a long period of time underwater. Just as it seems that Nasica has disappeared with $5 million, Ace discovers the money in a nearby car, making him and Cosmo wonder if what Nasica predicted was really true . . .