Lizzie had get quite same letter as Kalen, she thought it was a joke at first. So she didn't by attention at first but same days later she saw that same letter again on her desk, when she looked for her book, what she had lost. 'Maybe it's true, let's find out' she thought and took that letter and went out, forgoting that she needed to find on book. She walked towards the Torchwood since note said Torchwood and Doctor.
She saw her old friend, with who she haven't had contact already years, Kalen Zayne. So she began to follow him, maybe she had gotten same letter too. She hoped since she was not sure where that Torchwood exactly was. Soon she saw him enter there, first she saw him unlock the door and she was not sure why he went that way in. She entered couple seconds after him and hided behind things what was there, she didn't want to be seen.
When she saw Kalen disappear from her sight with someone, she waited couple of minutes and then did break in there too. But she was caught too by the Jack Harkness.
"Again same teenager, but this time girl," that man said with sigh. "Sorry, but...," she said but couldn't finish what she wanted to say since Jack didn't let her finish, he asked from her: "What you want here now?" Lizzie took hers letter out and showed it to him and didn't say anything.
"You too," he said. "What's your name?" Jack asked then after it. "Lizzie Night," she said with smile. "This is a serious matter Lizzie. I am Jack Harkness and I knew the doctor. If this is a note from him then we need to get you to where he is now. Follow me," he then said. Liz had no other choice than follow him.
They went all over the place until they enterd a room with a strange contraption in it. Stopping Jack messed with the machine then looked at Lizzie.
“Get in hoy. It will take you to the Doctor. Beware though. Your world will never be the same.“ he said then stepped aside. Liz entered the machine and the before she knew it he was somewhere else and she could tell it wasn't earth. She saw even little bit further Kalen. She walked towards him then, she wanted to ask if he got this stranger note or letter too.