Somebody has messed up my bookshelf by shoving a book into completely the wrong place.
Which is the intruder?
The wrong book is
Vicious Circles and Infinity (the second one)
the first letter of each other title spells out "my bookshelf".
Obviously wrong answer
... but it amuses me and it might amuse OP too. Perhaps the book that's in the wrong place is
it belongs over here, between Bleak House and The Murder of Roger Ackroyd.
Probably not the correct answer, because it's too straightforward, but each of the books is a proper book, but Birds Songs & Calls is multimedia - it comes with 2 CDs