I think its hard to beat John Cox book here. in the first 130 pages he covers ideas, positional themes, tactical possibities for both sides and he covers the various endgames that can arise and only after this will he start covering some theory so its perfect for actually understanding the Berlin defence on a high level
Best Books to Learn the Berlin Defence
The Berlin Defence by Igor Lysyj & Roman Ovetchkin (2012)
https://web.archive.org/web/20140627104938/http://www.chesscafe.com/text/hansen159.pdf
https://www.newinchess.com/media/wysiwyg/product_pdf/7076.pdf
The Berlin Wall by John Cox (2008)
https://web.archive.org/web/20140627050257/http://www.chesscafe.com/text/hansen115.pdf
https://www.qualitychess.co.uk/ebooks/TheBerlinWallInternetexcerpt.pdf
The Modernized Berlin Wall Defense
https://www.newinchess.com/media/wysiwyg/product_pdf/8228.pdf
The Berlin Defence Unraveled
https://www.newinchess.com/media/wysiwyg/product_pdf/9048.pdf
(I don't know about you, but I do not think that I would want to try to read any of these books.)

The Berlin Defence by Igor Lysyj & Roman Ovetchkin (2012)
https://web.archive.org/web/20140627104938/http://www.chesscafe.com/text/hansen159.pdf
https://www.newinchess.com/media/wysiwyg/product_pdf/7076.pdf
The Berlin Wall by John Cox (2008)
https://web.archive.org/web/20140627050257/http://www.chesscafe.com/text/hansen115.pdf
https://www.qualitychess.co.uk/ebooks/TheBerlinWallInternetexcerpt.pdf
The Modernized Berlin Wall Defense
https://www.newinchess.com/media/wysiwyg/product_pdf/8228.pdf
The Berlin Defence Unraveled
https://www.newinchess.com/media/wysiwyg/product_pdf/9048.pdf
(I don't know about you, but I do not think that I would want to try to read any of these books.)
I second this

The Berlin Defence by Igor Lysyj & Roman Ovetchkin (2012)
https://web.archive.org/web/20140627104938/http://www.chesscafe.com/text/hansen159.pdf
https://www.newinchess.com/media/wysiwyg/product_pdf/7076.pdf
The Berlin Wall by John Cox (2008)
https://web.archive.org/web/20140627050257/http://www.chesscafe.com/text/hansen115.pdf
https://www.qualitychess.co.uk/ebooks/TheBerlinWallInternetexcerpt.pdf
The Modernized Berlin Wall Defense
https://www.newinchess.com/media/wysiwyg/product_pdf/8228.pdf
The Berlin Defence Unraveled
https://www.newinchess.com/media/wysiwyg/product_pdf/9048.(I don't know about you, but I do not think that I would want to try to read any of these books.)
I second this
wait I thought you did not like the Berlin
Read the bottom line that I bolded

The Berlin Defence by Igor Lysyj & Roman Ovetchkin (2012)
https://web.archive.org/web/20140627104938/http://www.chesscafe.com/text/hansen159.pdf
https://www.newinchess.com/media/wysiwyg/product_pdf/7076.pdf
The Berlin Wall by John Cox (2008)
https://web.archive.org/web/20140627050257/http://www.chesscafe.com/text/hansen115.pdf
https://www.qualitychess.co.uk/ebooks/TheBerlinWallInternetexcerpt.pdf
The Modernized Berlin Wall Defense
https://www.newinchess.com/media/wysiwyg/product_pdf/8228.pdf
The Berlin Defence Unraveled
https://www.newinchess.com/media/wysiwyg/product_pdf/9048.(I don't know about you, but I do not think that I would want to try to read any of these books.)
I second this
wait I thought you did not like the Berlin
Read the bottom line that I bolded
wtf I thought it said booser I am dumb lol
It did, I edited it
It was a typo
Title really says it all. I'm looking for a book to learn the Berlin Defence in the Ruy Lopez. Here it is for those unfamiliar: