Book reviews: The best reads for teens this festive season

Turtles all the Way Down (Penguin, £14.99) is the much-anticipated new release from bestselling American author John Green. When Aza’s fearless best friend Daisy first suggests they should investigate the case of a missing billionaire in a bid to win the $100,000 reward, Aza is reluctant. She is uneasy about using her former friendship with the missing man’s son, Davis, to gain information. Not wanting to disappoint her best friend though, Aza tags along and soon she and Daisy get tangled up in Davis’s life. As the plot thickens Aza and Daisy’s relationship is put under increasing strain as the ever-tightening spirals of Aza’s OCD threaten to overwhelm them both.