§ Of Beren and Lúthien The Silmarillion

Thus they broke off the hunt and returned to Nargothrond, and Lúthien was betrayed; for they held her fast, and took away her cloak, and she was not permitted to pass the gates or to speak with any save the brothers, Celegorm and Curufin. For now, believing that Beren and Felagund were prisoners beyond hope of aid, they purposed to let the King perish, and to keep Lúthien, and force Thingol to give her the mightiest of princes of the Noldor. And they did not purpose to seek the Silmarils by craft or war, or to suffer any others to do so, until they had all the might of the Elf-kingdoms under their hands. Orodreth had no power to withstand them, for they swayed the hearts of the people of Nargothrond; and Celegorm sent messengers to Thingol urging his suit.