Following NPC and secret message door?

REWORDED= I guess no one understood what i was getting at.

I am wanting to know how i would script a door that would open if a specific word was said in game chat, any idea on how to do that?

I am also wondering how you would script a npc to follow you when you turned around, like morgennes NPCs. (Check her game out) Im very curious, if you have any info on how i would formulate the script tell me. i am NOT asking for you to MAKE me a script. Obviously. I want to learn to DO IT MYSELF. If i can learn how to do it i wont be here much longer, thank you for your time.

For the first one you do something as simple as:

--LocalScript

local ply = game.Players.LocalPlayer
local key = ""
local door = game.Workspace.Door

ply.Chatted:connect(function(msg,rcp)	--message, recipient
	if msg == key and door.CanCollide then
		door.CanCollide = false	--Not needed if your door relies on a hinge, also make sure the door is anchored if not
	end
end)

Don't know who or what that is so I'm gonna assume from your description that it's a chase on sight npc:

--Localscript again
local ply = game.Players.LocalPlayer
local cam = game.Workspace.CurrentCamera	--Player's current camera
local npc = game.Workspace.Npc
local runService = game:GetService("RunService")	--Better than while loop imo

local function isLooking()
	local val = npc:FindFirstChild("Target").Value
	if not val or val and not val.Parent then
		local pos = cam:WorldToScreenPoint(npc.PrimaryPart.Position)	--Gets a points position on the screen
		local maxDistance = 100 --Change to whatever works for you
		local distance = (npc.PrimaryPart.Position-ply.Character.PrimaryPart.Position).magnitude	--Gets distance between two parts

		if distance <= maxDistance and pos.Z > -1 then	-- -1 means its behind the camera
			npc:FindFirstChild("Target").Value = ply.Character
		end
	end
end
runService:BindToRenderStep("isLooking",0,search())

Put this in a script under the Npc:

local target = script.Parent:FindFirstChild("Target")

target.Changed:connect(function(val)
	--Code to move the character around because I'm too tired to write anymore
end)

No clue how any of this performs on a server or has any errors, but hope it helps.