- "I don't even know that we'd have to make a move, really. Just kind of sit back and let these dumbasses get themselves killed. We wouldn't even have to get our hands dirty. "
- —Mercer to George about the Commonwealth [src]
Nothing is known about Mercer's life prior to or as the outbreak began except at some point he became a member of The Commonwealth and was promoted to the rank of 'Officer' as suggested with the unique color of his armor compared to other soldiers.
Mercer is watching over Sebastian who is with Kayla. Once walkers got too close to them, Mercer saves them, only for Kayla to yell and walk back to the Commonwealth and Sebastian yell at Mercer for ruining his date. Mercer is later talked down to by Sebastian's mother Pamela. Later Mercer is talking to George about over throwing Pamela, to which Siddiq overhears.
This list shows the victims Mercer has killed:
- Numerous counts of zombies and unnamed people
Mercer is Sebastian's personal bodyguard. Sebastian is verbally abusive to Mercer despite Mercer saving him from numerous counts of walkers which resulted in him ruining Sebastian's date. Mercer hates Sebastian strongly, but holds his tongue when around him. It's possibly that Sebastian sees Mercer as well as the other solders as expendable.
Mercer and Princess are on good terms. She is romantically attracted to Mercer, when he saves her from a herd of walkers she kisses him. So far it is unclear if Mercer shares similar feelings towards her.