  We report on a novel scheme based on the chiral Lagrangian. It is used to
analyze pion-nucleon scattering, pion photoproduction, and nucleon Compton
scattering. Subthreshold partial-wave amplitudes are calculated in chiral
perturbation theory and analytically extrapolated with constraints imposed by
electromagnetic-gauge invariance, causality and unitarity. Experimental
quantities are reproduced up to energies $\sqrt{s}\simeq 1300$ MeV in terms of
the parameters relevant at order $Q^3$.
