Need help cycling through an array with a 'for' loop.

Ok, I am attempting to create a tile-based turn-based game. I am in the early stages of it and am trying to just get my fog-of-war / tile assignments to work. The way it should play is that you have scouts and you send them to a tile that is "fogged out" it sets a bool variable curScouting to true. Then when the turn is over (henchmen assigned to tasks) you hit the end turn button. I am trying to set up an array of strings to hold the tile-names (based on coordinates from center, center eg. -2 / -2). I then want the EndTurn script to step through each map to access the Fog_Tile script (on each tile) where I can check for the curScouting flag and set some more flags that result in the tile being revealed. I am running into errors cycling through things. The error message I get is "NullReferenceException: Object reference not set to an instance of an object EndTurn.OnMouseUp () (at Assets/Reclamation/EndTurn.cs:33)"

Here is my script: "using UnityEngine; using System.Collections; using System.Collections.Generic;

public class EndTurn : MonoBehaviour {

 public string[] Map = new string[] {"-2 / 2", "-1 / 2", "0 / 2", "1 / 2", "2 / 2", "-2 / 1", "-1 / 1", "0 / 1", "1 / 1", "2 / 1", 
     "-2 / 0", "-1 / 0", "Castle", "1 / 0", "2 / 0", "-2 / -1", "-1 / -1", "-1 / 0", "-1 / 1", "-1 / 2", "-2 / -2", "-1 / -2",
     "0 / -2", "1 / -2", "2 / -2"};
 private int mapTiles = 25;
 
 public Henchmen scouts;  // points to Henchmen script to manipulate scout henchy #
 public Fog_Tile scouting; // points to Fog tile script to manipulate fog flags


 void Start () 
 {
 scouts = GameObject.Find ("Castle").GetComponent();    
 
     
 }
 
 
 void OnMouseUp()
 {
 for (int i = 0; i < (mapTiles - 1); i++)    
     {
 
         scouting = GameObject.Find (Map[i]).GetComponent();            
         if (scouting.curScouting == true)
         {
         scouting.curScouting = false;
         scouting.scouted = true;
         scouts.scouts += 1;
         
         }
         
         
     }
     
 }
 
 
 void Update () {
 
 }
 
 
 
 
 

} // end of line"

SO - I've set up a for loop and am trying to use the variable 'i' that I use to advance to loop to also advance the array (Map[i]) so it will step through each tile name and can then access the Fog_Tile script on it. so... what am I doing wrong here?

I'm thinking PERHAPS I want to revers my logic and use my EndTurn script to set a flag and have each individual Fog_Tile script check for that flag; and I think I could pull that off, but want to understand where I am going wrong with for loops and arrays in case I want to use that in the future.