While on a ferry going to Ash and his friends' next destination, the group looked out into the woods and saw Suicune. Not knowing what it was, they called Professor Oak and described it to him. Professor Oak said that it was in fact a Suicune and told the group all about it. Ash then asked if Professor Oak ever saw a Suicune, and he replied with yes. He then asked where Ash precisely saw the Suicune. Ash told the professor where he saw it and before Professor Oak could respond, the ferry owner called for Ash. Ash, Misty, and Brock then quickly said goodbye to the professor.
A while later, Suicune saw the Iron-Masked Marauder making Celebi destroy the forest and saved Ash and Sam from falling off the monster that Celebi created. Suicune eventually got caught in the monster's hand, nearly immobilized. It managed to struggle out of its grip, buying time for Ash and Sam. They eventually succeeded into saving Celebi from the Iron-Masked Marauder.
In order to heal Celebi, Ash and his friends brought Celebi to the Lake of Life, but because it was corrupted, its healing powers didn't work on it. Suicune then purified the water, but the water still didn't heal Celebi. Realizing Celebi is dead, they mourned, until many other Celebi came from the sky and revived it.
Before Sam and Celebi went back to the past, the group thanked Suicune for its help and said goodbye to it, after which it ran off.