Catch Your Death by Lauren Child (Ruby Redfort #3)

Ruby Redfort: undercover agent, code-cracker and thirteen-year-old genius - there's nothing average about her. Only this time it's an adventure in the wild, and it'll take all Ruby's got just to survive...

This time, tigers are roaming the streets of Twinford, and it looks like someone has deliberately released some very rare and very dangerous animals. Things are going to get wild - and Ruby is going to get badly lost in the wilderness. The question is: will she ever make it out alive? Well, as always, you wouldn't want to bet against her...