1996, Penguin, Ringwood
Josie and Ivan are two adolescents from the near future who are on a time travel holiday when they become stranded in the past. They must learn to survive in the wilderness with a tribe of Neanderthals.
This was a very interesting premise and I like Kelleher's exploration of time travel theory and the nature of time. However, at times, it felt a little too much like it was trying to be educational from a historical viewpoint ... it seemed to read like a documentary about Neanderthals and their life.
Link to journal at bookcrossing