I love the grimdark sci-fi/fantasy universe Warhammer 40,000, but it’s hard to find one book that serves as a great entry into that universe. If you’re up for it, just pick up a 40k book that interests you, dive in and be ready to Google a lot of terms as you go. It’ll be worth it.
Otherwise, I recommend a subscription to Warhammer Plus, the new streaming service featuring shows which take place in the ridiculous but awesome world of 40k. You may still have to do some Googling to figure out what Necrons are or who Rogal Dorn was, but I think you’ll find it worth the effort.
If $60 for a year subscription seems steep, you can try a $6 monthly subscription, or just send your loved one the link below to a film made by a 40k fan who is now helping shape the content on Warhammer Plus. The two probably have a lot in common.