  There has long been speculation about the nature of the $\sigma$-resonance.
For three decades Jaffe has argued for a tetraquark composition, while others
have claimed it is largely a glueball. A key pointer to its nature is its
coupling to two photons. Consequently, there have been recent proposals to
observe this important scalar hiding in $\gamma\gamma\to\pi^0\pi^0$. We show
here that the $\sigma$ is already crouching in this cross-section exactly as
measured twenty years ago. What is new is that precise knowledge of the
position of the $\sigma$-pole, provided by the analysis of the Roy equations,
now allows its two photon coupling to be accurately fixed. Its two photon width
is found to be $(4.1 \pm 0.3)$ keV, a value far too large for a gluonic, or
even a tetraquark, state.
