Once Upon a Time 5x4 - The Broken Kingdom

After receiving a cryptic warning from Lancelot about Arthur'sintentions, Mary Margaret realizes Arthur may be the heroes'biggest threat, but when she is unable to convince David ofthe danger, she takes matters into her own hands. Meanwhile,Hook's unwavering love for Emma provides a glimmer of hope inher struggle against the unrelenting voice of Rumplestiltskin.In a Camelot flashback, Guinevere senses that Arthur is losinghis way, consumed by his obsession with making Excaliburwhole, so she sets out with Lancelot on her own quest into theheart of darkness. In Storybrooke, Dark Emma unleashes asecret weapon in the next phase of her plan to find the bravesoul she needs to draw Excalibur from the stone.