He had helped remodel Matheson Catcher's cellar and attic. When he returned on Christmas Eve 1799 for more work, Catcher's use of the amaranth had converted his cellar into an unTARDIS. Later when he was in the actual TARDIS, the Interface told him he was part of the first generation that had abilities defined enough to be called psychic and that there were more like him in France.
When the Seventh Doctor recovered the amaranth from Roz Forrester, he gave it to Daniel. After the Carnival Queen was banished again, he left it in the Woodwicke town Christmas tree on Paris Street. He and Marielle Duquesne then went to France to find more psychics like themselves. (PROSE: Christmas on a Rational Planet)