Ronald and the gang out on a journey to Grimace Island where Grimace's species is discovered.

Hamburglar tricks the gang into believing that aliens have come to Earth so that he can steal McDonaldland's hamburgers without interference from them, which costs him their trust in him when they find out. Later, Hamburglar gets abducted by real aliens after foolishly accepting an offer to go on vacation with them, not realizing until too late that the vacation lasts thousands of Earth years. Despite being angry at him for his lie and prank, Ronald and his friends go on a mission in outer space to rescue Hamburglar.

Hamburglar is upset that he forgot Ronald's birthday and does not have a present for him until an evil mad scientist named Professor Thaddeus J. Pinchworm gives him tickets to a fake amusement park called Birthday World.

While helping Franklin clean up his father's lab, Ronald and his pals stumble across a time machine in which Hamburglar dreams up a crazy scheme to use the time machine to get out of cleaning and they end up getting lost in time.

The gang travels to a Scottish expedition known as McDonaldland Loch where Sundae's cousin Scotty lives. They also come across a plot by a mad scientist named Stiles and his assistant Pip's attempt to build a replica of the Loch Ness Monster in order to make money from the discovery.