Ferenc Dezső Weisz (March 4, 1876 – June 12, 1945), known as Theodore "Dash" Hardeen, was a Hungarian-American magician and escape artist who was the younger brother of Harry Houdini.

Hardeen was the first magician to conceive escaping from a straitjacket in full view of the audience, rather than behind a curtain.

Hardeen, like his more famous brother Harry Houdini is a great favourite in the magical world.

[3] Houdini, in his will, requested that all his files be given to Hardeen and destroyed ("I give, devise and bequeath to my brother, Theodore, Professionally known as "Hardeen" all my theatrical effects, new mysteries and illusions and accompanying paraphernalia, to be burnt and destroyed upon his death.

[6] In 1945, while planning on writing a book about his brother, Hardeen went to Manhattan's Doctors Hospital for a simple operation.

[7][8] During his final show on May 29, 1945, in Ridgeway, Queens,[9] Hardeen named his chief assistant, Douglas Geoffrey, his official successor.

[12] Hardeen appears as a character in season one of Boardwalk Empire, played by Remy Auberjonois.