Reprints X-Men (1963) #44 plus a 5-page story titled "The Warning" from Mystery Tales (1952) #30, June 1955.
"Red Raven, Red Raven...!"
Warren escapes the bonds of Magneto as Scott sends him to get help from the Avengers, but Warren is delayed as he discovers a fortress disguised as an island. He meets the Red Raven, the last of his people and how he is responsible for that fact. But the Red Raven must keep his secret as he sets Warren free and sinks the island again. Warren continues on to get the Avengers to help save the X-Men.