Ad Victoriam

Ad Victoriam is a Brotherhood of Steel main quest and achievement in Fallout 4.

Bugs

 * While following Liberty Prime he may stop walking and not continue, make sure to regularly quicksave in case this happens. This can be fixed by shooting him (which won't cause him to become aggressive) or by fast travelling to C.I.T. ruins, or by fast travelling to the institute and completing Banished from the Institute.
 * After crossing the river and eliminating all synths, Liberty Prime may get stuck and keep throwing mini-nukes on the waiting shed. You have to fast-travel to the nearby locations like Bunker Hill or Weatherby Savings & Loan to "reload" his position.