The Turkish Old Man ran an antique store that served as a direct telephone line to Gideon Malick before the collapse of HYDRA. He was tasked with welcoming people who stated the correct code phrase, "Parizad sent me; we went to Princeton together."
Failing to assassinate Dr. Andrew Garner, Werner von Strucker desperately visited the antique store to ask an ally of his father's, Gideon Malick, to protect him from Grant Ward, who was angry with Strucker for letting him down. Strucker went to the Turkish Old Man, told him the appropriate phrase, and was ultimately allowed access to Malick.
Months later, S.H.I.E.L.D. interrogated Strucker and learned the necessary code phrase to contact Malick. Director Phil Coulson arrived at the antique store and was given access to Malick's phone by the old store owner, who had confiscated his metal belongings, including his prosthetic hand.