Eddie Redmayne stepped in to rescue fellow Brit Felicity Jones after the actress' dress became dangerously caught on an escalator.

The pair attended a screening of their new movie The Theory of Everything at the Museum of Modern Art (MoMa) in New York City on Monday (20Oct14), and disaster nearly ensued when Jones' long gown became caught in a moving staircase.

Redmayne rushed to her aid by pressing the emergency stop button before helping to free her, according to New York Post gossip column Page Six.

An onlooker tells the publication, "The back of Felicity's long black dress suddenly got caught in the escalator... (Redmayne) hit an emergency button... (and then rushed to) help disentangle her... Eddie came to Felicity's rescue... It could've been disastrous for a host of reasons."

The pair plays physicist Stephen Hawking and his first wife, Jane, in the new movie.