Evolution of two massive stars that leads to the formation of the moderate mass ratio (q = 0.12) BH-NS (14.7 + 1.8 M_⊙) merger (model M230). The top panel shows the mass evolution of the primary and secondary stars, while the bottom panel shows the changes in the semimajor axis and eccentricity. Evolution from ZAMS to the BH-NS system formation takes 10.5 Myr, and then it takes another 2.7 Gyr for the two compact objects to merge and produce gravitational wave radiation that is potentially detectable by LIGO/Virgo. No mass ejection (no kilonova or short GRB) is expected in this case.