Mallory says " Dr Watson, come here" when establishing communication with the fire-creature. This is an allusion to the first recorded telephone conversation between Alexander Graham Bell and his assistant.
At the end, just before Quinn Mallory walks into the portal, he tells the flame, "We got to get you home." It has been well established that the Sliders cannot go back to a world after they've left it. However, the flame says it has "photon solar-wave propulsion and time-slip dimensional access" that allows it to return to its earth.