A homeless woman's corpse is found in the streets, but her liver was removed while she was still alive, as required for safe organ transplants. Her unusually well balanced diet allows tracing her to a shelter where homeless Walter Mason identifies her as his widowed friend Patsy. After another fatal 'organ-donation', Mark plays the part of a healthy homeless man. The sleuths find that the free clinic which examines the homeless in that area, run by Cheryl Dante and Tom Winston, is linked to Howard Mitchell's foundation's Beverly Hills private practice, where organs could be sold for a fabulous fortune. Steve finds Tom has a dirty record, Mark suggests a trap...