Invaders #20 is a key Bronze Age Marvel issue featuring the first full appearance of Brian Falsworth as Union Jack II, making it one of the most important books in the series outside of the debut of Baron Blood and the original Union Jack. The issue also includes an appearance by Adolf Hitler and reprints the historic origin of Namor from Motion Picture Funnies Weekly, adding additional historical significance to the book. This professionally graded CGC 9.6 with White Pages copy is ranked as the Second Highest Graded on the CGC Census, with only 9.8 copies grading higher. For Bronze Age Marvel collectors and registry participants, 9.6 examples represent an attractive combination of scarcity, eye appeal, and value.