Very different from Night of the Eagle was Alwyn's final work for Disney, recorded at the beginning of March 1962. His first plan for In Search of the Castaways (1962) was a chorus “sung like a sea shanty”, based on Richard M. and Robert B. Sherman's main theme “Castaway”. The plan was later abandoned in favour of an orchestral arrangement, but it was a sensible one for what was billed as “Jules Verne's fantasy-adventure”. It is a tale of a young girl, Mary Grant (Hayley Mills), who sets off with her brother Robert (Keith Hamshere), the eccentric Professor Paganel (Maurice Chevalier), and Lord Glenarven and his son John (Wilfred Hyde-White and Michael Anderson jr respectively) in search of her lost sea-captain father.

As in earlier whimsical yarns such as The Crimson Pirate and The Million Pound Note, Alwyn's music track is brim-full with fertile inventiveness, spontaneity, and energy. Thus the sequence in which our characters are hurtled on a toboggan-like boulder down a snow slope is accompanied by brassy circus music. When their rocky carriage enters an icy tunnel, with delicate glass-like stalactites and stalagmites, an echoing trumpet sounds a fanfare (based on the “Castaway” motif), which gives way to light bells when Paganel tests the echo with his yodel. Re-emerging from the tunnel, the circus refrains leap in again on a breathlessly fast piccolo solo - until the party crash and, via some Latin American chords as they pick themselves up, gives way to a “palm court” waltz when a giant condor takes Robert off. Or there is the short but humorous sequence of crotchety Lord Glenarven dubiously tasting an omelette concocted by Paganel to a halting bassoon and tremulous strings, a sequence that is nothing without its musical score. Just as impressive is the Viennese waltz accompanying Robert as, held by a home-made rope around his feet, he swings upside down across a wide and frighteningly deep chasm.

Apart from “Castaway”, the Shermans composed three other songs, all except one incorporated by Alwyn into the underscore. There are also sequences of natural native chanting. The music track thus presents a rich diversity, to which Alwyn's score, consciously and artfully moulded, contributes the major share.

Alwyn evidently found satisfaction in layering his filmscores with meaning, enjoying this influence over a film's emphasis.