Get vector that is opposite point knowing the middle and starting one

[cowsoncows]

That’s only half of the work; (Boss - Player) is just the vector from the player to the boss. Next you need to add the negative of this vector to the player’s position.

local vector = game.ServerScriptService.WhoIsBoss:
Invoke().HumanoidRootPart.Position - human.Parent.Head.Position
local negativeVector = -vector
dot.Position = human.Parent.Head.Position + negativeVectr

Try that