Because of its semi-autobiographical nature, some of "A Scanner Darkly" was torturous to write. Tessa Dick, Philip's wife at the time, once stated that she often found her husband weeping as the sun rose after a night-long writing session. Tessa has given interviews stating that "when he was with me, he wrote "A Scanner Darkly" under two weeks. But we spent three years rewriting it" and that she was "pretty involved in his writing process [for "A Scanner Darkly"". Tessa stated in a later interview that she "participated in the writing of "A Scanner Darkly"" and said that she "consider[herself the silent co-author". Philip wrote a contract giving Tessa half of all the rights to the novel, which stated that Tessa "participated to a great extent in writing the outline and novel "A Scanner Darkly" with me, and I owe her one half of all income derived from it".