She ignored it as realisation hit. While the Doctor knew what they were up against, Luke had no idea. She needed to contact him - now.

As Sarah Jane continued her frantic drive to the school, she hit the speed dial on her phone. The ring only lasted for a moment. "Luke?"

"Sarah Jane," came a boy's voice on the other end.

"I was wrong. It is aliens," she replied, giving the Doctor a glance. One of them was here with her, one who was typically a rather good sign that something disastrous was going on.

"Yeah, I know." The roar that followed frightened Sarah more than she cared to admit.

"Right. Listen, smell or vinegar, got it? They don't like vinegar, Luke. And be careful."