Thor (1962 Marvel 1st Series Journey Into Mystery) #153

Cover pencils by Jack Kirby, inks by Vince Colletta. "But Dr. Blake Can Die!", script by Stan Lee, pencils by Jack Kirby, inks by Vince Colletta

Loki has stolen Thor's hammer and fled to Midgard; Thor and Sif pursue him, but without the hammer Thor changes into Don Blake as Loki attacks them. Loki escapes, but Sif is injured in the fight, and Dr. Blake must operate to save her life. Appearances by Balder, Karnilla, and Odin. 

36 pgs., full color. $0.12. Cover price $0.12.