Just add a twist: Metallosupramolecular architecture design is used to create anti-cancer agents with high activities in human breast cancer cell lines. Three isomers, which comprise a nonhelical metallocyclophane, an unsaturated double helicate, and a new type of double helicate, bridge the fields of metallosupramolecular architecture and anticancer drug design (picture: double-helical trans/cis isomer; red Ru, green Cl).