"Run!" the Doctor shouted, taking off down the corridor. Rose quickly followed suit. Someone, or something, was following them. The lights were flickering and it was becoming difficult to see where they were going. Rose could hear the footsteps behind them growing louder, so she quickened her pace. She rounded the corner after the Doctor and nearly ran straight into him. He had stopped, for some reason or another.
"What are you-?" she began to ask before he cut her off.
"Shh!" he said, softly pressing his index finger against her lips. He pulled her into a small space behind a closet, without any explanation. Whatever was chasing them was getting closer, but the Doctor clearly thought it better to hide from it than attempt to outrun it.
They stood quietly, and they heard the creature running right past them. After a moment, all was silent apart from their breathing. Rose became very aware of how close the two of them were in the confined space. Suddenly, the Doctor leaned forward and pressed his lips against hers. It was over as quickly as it had started.
"For luck!" he exclaimed, grinning. Then he grabbed her hand and set off after the creature.