GJ 3473 is a cool M-dwarf (about 0.36 solar masses, 3,347 K, 0.36 solar radii), 27.4 light-years from Earth. GJ 3473 b is a 1.9-Earth-mass planet, with an orbital period of 1.2 days, at 0.016 AU from its star, and an equilibrium temperature near 773 K, discovered in 2020 via transit. GJ 3473 c is a 7.4-Earth-mass planet, with an orbital period of 15.5 days, at 0.088 AU from its star, and an equilibrium temperature near 329 K, discovered in 2020 via radial velocity. Mutual gravitational tugs between the planets can slowly reshape their orbits, preserving clues to the system's assembly.