The family becomes marooned after a summer storm shipwrecks them on an island, and Phineas, Ferb and Isabella use the opportunity to build a Swiss Family style tree house. Meanwhile, Candace tries to get them to build a boat so she can get back in time for Jeremy's party. After finding out what "big laundry" meant, Dr. Doofenshmirtz uses free monkey labor to boost a new laundromat business.