Suggest me a book for my apathetic brother

Hi everyone,

Lately, my younger brother has been feeling down and lacking motivation. I know he loves books and plan to gift him some, so I want to ask for any suggestions about great book that people read in a rainy day like this. Usually he likes to read adventurous fiction or thriller novels, but anything is welcomed since there may be others searching for this kind of topic.

Thank you so much!