She first appeared sitting in a car driven by Eddy, driving along the road of Muraille Coast. They stopped when they spotted Ash and his friends, who were in panic as Ash's Pikachu had just been poisoned by a Skrelp. Lindsey immediately offered help, looking for a first-aid-kit. She treated Pikachu and he quickly got better. She and Eddy then introduced themselves to the group. They explained that they were going to dive in a specific area in the sea that same day, looking for the remains of the S.S. Cussler that had crashed into an iceberg long ago. As Ash and his friends got very excited about what they were told, Lindsey and Eddy agreed to let them help on their exploration.
She was later accompanied by Ash and Serena in her submarine. They were quickly swept away by some strong currents, however. In the process, they found the remains of the S.S. Cussler. However, they also discovered Team Rocket was also investigating the ship. They entered the ship and confronted the trio. Team Rocket managed to escape with the S.S. Cussler's treasure, however, and while doing so, they caused the remains of the sunken ship to sink away completely. Lindsey, Ash, and Serena managed to escape in time, and they told the Pokémon living around to ship to help in stopping the S.S. Cussler from sinking away. When that plan succeeded, Lindsey was told by Eddy to come back to the surface as the strong currents would appear again soon.