YoRHa: Pearl Harbor Descent Record - A NieR:Automata Story, Vol. 4

It is the year 11941. No. 2 and No. 4 have infiltrated the enemy server base in Mount Ka’ala so that they may take back the Earth from machine lifeform encroachment. Resistance members Rose and Gerbera face off against two machine girls on the server room floor. As those on the satellite base begin to feel less certain about their support for YoRHa, the machine girls reveal the purpose behind Project YoRHa and the objective of the operation, as decided by the Council of Humanity. In this final volume, how will this battle against the machine lifeforms end?