Scur noticed a red glow shining against the wall and was getting closer and closer. He soon realized it was Zion or another Jedi turned to the Dark Side, which he doubted.
Soon he could hear the humming of the Lightsaber and he decided to hide in the shadows and watch where Zion goes, and follow him, maybe catch him offguard. Zion turned the corner slowly and the red saber lit the room with a red glow. Scur hid even further making sure Zion didn't see him.