Designed to compete with DC Comics' successful relaunching of House of Mystery and House of Secrets into traditional horror comics, Tower of Shadows, like its companion comic Chamber of Darkness, sold poorly despite such notable talent. After its first few issues, the title began including reprints of pre-superhero Marvel monster stories and other SF/fantasy tales from Atlas Comics. After the ninth issue, the title changed to Creatures on the Loose, and the comic became a mix of reprints and occasional sword and sorcery/SF series.
Steranko's lead story in the first issue, "At the Stroke of Midnight,", won a 1969 Alley Award for Best Feature Story. Its creation led to a rift between the celebrated Steranko and editor Lee that caused Steranko to stop freelancing for Marvel, the publisher that had showcased his highly influential work in such titles as Strange Tales and Nick Fury, Agent of SHIELD. Lee had rejected Steranko's cover design, and the two clashed over panel design, dialog, and the story title, initially "The Lurking Fear at Shadow House".