Straight Lines And Pair Of Straight Lines

A ray of light coming from the point \(\mathrm{P}(1,2)\) gets reflected from the point \(\mathrm{Q}\) on the \(x\)-axis and then passes through the point \(R(4,3)\). If the point \(S(h, k)\) is such that \(P Q R S\) is a parallelogram, then \(hk^2\) is equal to: