Mithias gasped softly as the other vampire made a bold offer. Either Adam knew his mind was unreadable, or he knew that Mithias lacked the gift to read it, but in either case, blood was a surefire way to see the truth. Through drinking blood, a vampire could see glimpses of the host's soul. Their memories, knowledge, and emotions could be read easily, until they died. The heart was laid bare to the one that drank. 

The golden-eyed vampire hesitated. This could have been a trap. If Adam were stronger, he could flip the bite on Mithias and literally have him by the neck. Adam certainly portrayed his confidence as the red trickled down his neck. Mithias drew closer. He looked dam in the eyes as he parted his lips cautiously. Sometimes, you just had to live on the edge. 

Embraced, Mithias cleanly sank his teeth into Adam's jugular and pulled. He could see what Adam had seen, everything in his being that made him who he was, but only fragments at a time. The blood had memory, and he didn't have much time to sort through it. He focused on Alucard, on Adam's sincerity.