One of the overarching goals in nuclear physics is to rigorously compute properties of hadronic systems directly from the fundamental theory of the strong interaction, Quantum Chromodynamics (QCD). Resonant hadrons, and some loosely bound states, can be studied by looking at the energy dependence of the reaction rate of the multi-particle asymptotic states associated to them. The form factors of these states can be found via analytic continuation of the two-particle transition rate induced by the current of interest, which can be studied non-perturbatively using lattice QCD.  In this talk we will describe the procedure to connect finite volume data to infinite volume transitions involving two-hadrons in both the initial and final states, and apply it to a non-relativistic toy model lattice theory.