Pokémon mystery dungeon

What lies inside part six

"We are one fourth of the way there!" Thunder exclaimed.
"Yah we all know that."
Thunder rolled his eyes.
The group continued to follow snow but it was a sandstorm so it was hard to see.
"Oww! That sand hurts!"
"Yah we all know! And you can't heal in it."
They got to a Pokémon but easily battled it... but they didn't heal afterwards.
"Why am I not healing?"
"Der... didn't I already tell you why!"
"We have to get to a floor that there isn't sand to heal."
Snow continued to lead them to the stairs despite all of their annoying talking.
Soon they got to the stairs and were relieved to see when they went down that it was the lush green forest again.