Katie Holmes is mourning the loss of her beloved friend and former Dawson's Creek costar James Van Der Beek. "James, thank you. To share space with your imagination is sacred - breathing the same air in the land of make-believe and trusting that each other's hearts are safe in their expression," wrote Holmes, 47, in a handwritten letter shared via Instagram early Thursday, February 12. She continued, "These are some of the memories, along with laughter, conversations about life, James Taylor songs - adventures of a unique youth ..." "Bravery. Compassion. Selflessness. Strength.