Fergus or Wyatt, decided
Save Fergus. His timeline gives permanent maximum health upgrades; Wyatt's gives temporary armour. Neither blocks the story, only about a dozen optional rooms.
Ten minutes into The New Order, a surgeon gives you a choice: save Fergus or save Wyatt. It is the single most consequential decision in the game, it cannot be undone without a new playthrough, and it changes what you can upgrade for the next twelve hours.

What the choice actually changes
Three things: a story branch, a traversal ability, and an upgrade track. The story branch is cosmetic. The other two are not.
| Save Fergus | Save Wyatt | |
|---|---|---|
| Story timeline | Fergus survives, Wyatt is lobotomised | Wyatt survives, Fergus is lobotomised |
| Traversal ability | Hotwiring | Lockpicking |
| Upgrade track | Maximum health, permanently | Temporary armour |
| Perk access | Health upgrades stack for the whole game | Armour is consumable, not permanent |
Why health beats armour
Fergus's timeline lets you raise your maximum health by ten points per upgrade, permanently, for the rest of the run. Wyatt's gives you armour that expires.
Health that persists is worth more than armour that does not. It affects every fight, it survives every chapter transition, and it stacks with the Vampire perk that turns takedowns into healing. Armour refreshes between levels and gets chewed through in a firefight.
If you want the easier game, save Fergus. If you want to see the other half of the writing, save Wyatt on a second run.
What hotwiring and lockpicking open
Both let you reach optional areas, and neither blocks the main path. Panels and doors differ: hotwiring uses a wire-matching minigame with the thumbsticks, lockpicking uses a pick-and-tension minigame.
| Obstacle | Fergus timeline | Wyatt timeline |
|---|---|---|
| Hotwire panels | Yes | No |
| Locked doors | No | Yes |
| Optional rooms behind both | Some | Some |
| Main story path blocked | Never | Never |
You will not be locked out of a chapter or an ending by either choice. You will be locked out of about a dozen optional rooms, and some of those rooms contain collectibles.
What this means for 100%
Collectible progress and chapter select both work regardless of which timeline you are on. If you saved Wyatt and a Fergus-only hotwire room holds a collectible you want, you can replay that chapter on a save from the other branch.
Achievements are not mutually exclusive either. Both outcomes award their own achievement, so a single playthrough gives you one of the two and a second run gives you the other.
Which one to pick on a first run
Save Fergus. Permanent health is the more useful attribute in a game built around absorbing damage, and the health upgrades keep paying off in the late chapters when enemy density climbs.
Pick Wyatt if you have already finished the game once and want the other timeline, or if you specifically want the lockpicking minigames. Both branches are written to the same standard, so you are not losing content either way, only access.
Can you change your mind
No. There is no in-menu switch and no post-game option. Chapter select lets you replay the prologue and make the other choice, but that starts the timeline over from that point rather than merging it with your progress.
Perk counters live on your profile rather than the save, so a second run keeps everything you unlocked on the first. That makes a Wyatt playthrough on a completed profile considerably less painful than the first one.
The perk guide lists which perks are gated behind progress rather than this choice, and the characters page covers who Fergus is in the wider series.