KöMaL 2018 B4970

A line $e$ in the plane separates two given points $A$ and $B$ of the plane. On the line $e$, select points $P$ and $Q$ such that $\angle PAQ=90^{\circ}$. Show that there exists a point different from $B$ that lies on all circles drawn through $B$, $P$ and $Q$, independently of the choice of $P$ and $Q$.