Gnomeo and Juliet, along with their fellow garden gnomes, move from the countryside to a bustling city. Their idyllic new garden life takes an alarming turn when they discover that other gnomes from neighboring gardens have mysteriously disappeared. Gnomeo and Juliet enlist the help of the legendary detective Sherlock Gnomes, who, along with his loyal sidekick Watson, is determined to solve the mystery of the missing gnomes. Sherlock's investigative prowess and keen sense of deduction lead them through a series of perilous adventures across the city.

Sherlock is convinced that his arch-nemesis, Moriarty, is behind the kidnappings. As Sherlock, Watson, Gnomeo, and Juliet delve deeper into the case, they navigate various challenges and obstacles that test their resolve and teamwork. Along the way, misunderstandings and personal issues arise between the group, challenging their unity. As clues start to piece together a larger pattern, tensions heighten, forcing everyone involved to confront their greatest fears and make critical decisions about loyalty, bravery, and friendship.