It was filmed in Universal Studios on the largest sound stage, taking advantage of the process screen,[3] with a location shot of a beach in Malibu, California.

In the meantime, Barnaby will live with his uncle, Major Kevin Harrison, who resides on a remote, sparsely populated island, located 8 mi (13 km) from the mainland.

The two children constantly argue, with Chrissie believing Barnaby is telling fantastic lies about his uncle's exploits, though Frank does reveal himself as a policeman to her.

One night, Uncle Kevin, dressed in his wartime military beret and battledress (as he does on the cover of his book), visits a sleeping Barnaby and wakes him to go on an adventure with him.

The next day, Justine sees Barnaby perilously close to the edge of a high cliff and shouts at him, waking him out of his trance.

Based on Barnaby's previous lies and hysterical behavior, no one believes him, until Chrissie discovers the truth and gleefully suggests they kill Uncle Kevin first.

[citation needed] Cardi recalled that Nigel Green acted as a real life friendly uncle to him on the set, giving him tips on performing.

When shooting the actual scenes, the real tarantula was present, with Castle asking Cardi, "wouldn't it be fun to drop it on Nigel's chest?"