Watch The Only One full movie online Movies123. Watch The Only One 123movies online for free. The Only One 123Movies: Lucien Knops (Nand Buyl) is a grumpy old man. When his wife passes away, he moves in with his daughter Gerda. It doesn't take long before tensions rise and Lucien moves back into his old house, claiming that his new lover will move in with him. Gerda is worried that she will miss out on her father's inheritance; even more so when an interesting new woman moves in next door to Lucien.