While there is no single source to legally stream the entire Eisenhorn: The Omnibus
by Dan Abnett is widely considered one of the best entry points and a "peak of 40k writing". This collection follows Inquisitor Gregor Eisenhorn as he battles aliens, heretics, and his own moral decline. How to Get the Audiobook for Free
If you were searching for a of this title: be aware that legitimate free copies are not legally available (it’s published by Black Library, with audiobooks sold through Audible, Black Library, or sometimes library apps like Hoopla). Unauthorized uploads on YouTube or similar sites are pirated and often taken down quickly.