Question: how to buy a house raven rock?
Answer: Kill the ash spawn that are attacking Captain Veleth. [00:31]
Speak with Captain Veleth again. [03:40]
Head to Fort Frostmouth. [04:01]
Head over to Raven Rock mine. [04:32]
Enter the Severin Manor and recover the evidence (located in the locked safe in the master bedroom) [11:57]
Accept your reward. [13:45]