Let α, β and γ be real numbers such that the system of linear equations
x + 2y + 3z = α
4x + 5y + 6z = β
7x + 8y + 9z = γ − 1
is consistent. Let |M| represent the determinant of the matrix
M = [[α, 2, γ], [β, 1, 0], [−1, 0, 1]].
Let P be the plane containing all those (α, β, γ) for which the above system of linear equations is consistent, and D be the square of the distance of the point (0, 1, 0) from the plane P.
The value of |M| is ___.