import java.io.*;
import java.util.StringTokenizer;

public class Main {
    static int[] result;
    static int[] arr;
    public static void main(String[] args) throws IOException {
        Scanner sc = new Scanner(System.in);
        PrintWriter pw = new PrintWriter(System.out);
        int t = sc.nextInt();
        for (int i=0;i<t;i++){
            int n=sc.nextInt();
            arr = new int[n];
            result = new int[3];
            for (int j=0;j<n;j++){
                arr[j]=sc.nextInt();
            }
            if (arr[0]+arr[1]<arr[arr.length-1]){
                System.out.println(1);
                System.out.println(2);
                System.out.println(arr.length);
            }else{
                System.out.println(-1);
            }
           /* if (!search(0,0)){
                System.out.println(-1);
            }*/
        }
    }
    public static boolean search(int index,int count){
        if (count==3 && result[0]+result[1]<result[2]){
            display();
            return true;
        }else if(count==3){
            return false;
        }
        boolean take=false;
        for (int i=index;i<arr.length;i++){
            result[count]=arr[i];
            take=search(i+1,count+1);
            if (take){
                break;
            }
            result[count]=0;
        }
        return take;
    }
    public static void display(){
        int count=0;
        for (int i=0;i<3;i++){
            while(true){
                if (arr[count]==result[i]){
                    System.out.println(count+1);
                    count++;
                    break;
                }
                count++;
            }
        }
    }
    static class Scanner {
        StringTokenizer st;
        BufferedReader br;

        public Scanner(InputStream s) {
            br = new BufferedReader(new InputStreamReader(s));
        }

        public Scanner(String file) throws FileNotFoundException {
            br = new BufferedReader(new FileReader(file));
        }

        public String next() throws IOException {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }

        public int nextInt() throws IOException {
            return Integer.parseInt(next());
        }

        public long nextLong() throws IOException {
            return Long.parseLong(next());
        }

        public String nextLine() throws IOException {
            return br.readLine();
        }

        public double nextDouble() throws IOException {
            return Double.parseDouble(next());
        }

        public boolean ready() throws IOException {
            return br.ready();
        }

    }

}