Base of Operations
A pocket dimension which has an access point in an undisclosed apartment in Manhattan.
Avengers #69 (1969)
Recently, the Grandmaster has reformed and increased the powers of the Squadron Sinister with the Speed Demon, a new Doctor Spectrum, and an apparently resurrected Hyperion. Nighthawk declined to re-join the Squadron, and joined the Thunderbolts until he learned the only reason Songbird asked him to join was for his money, he quit and joined the Squadron Sinister to help defeat Baron Zemo and the Thunderbolts.