Ansel Elgort feared incurring Shailene Woodley's wrath on the set of their films.

The 20-year-old actor, who stars opposite the actress in 'Divergent' and 'The Fault in Our Stars', admits he almost didn't read the acclaimed book the latter film is based on before his audition but his co-star forced him to brush up.

He explained: ''I was on set with her on 'Divergent' and she said, 'Have you read it yet?' I couldn't lie to her, I said, 'No, I haven't.' She said, 'If you show up for the screen test and you haven't read it, I'll be so mad!'

''I was like, 'Oh crap, I've got to read this otherwise she's gonna be annoyed with me the whole time!' ''

Elgort read the novel, which follows the tragic love story of two cancer-stricken teens, and admits he was blown away.

He added to Bliss magazine: ''I literally couldn't put it down, it was so great. I read it over two days, which I've never done - I don't even read books! That's my only downside ... well, one of my downsides.''

Having starred in two book adaptations this year, the hunk admits he'd prefer to write a novel like 'Fault in Our Stars' rather than a big sci-fi adventure like 'Divergent'.

He explained: ''I don't know if I could write a big, epic story like 'Divergent'. I'd probably write something more about real life.''