1) Becomes complicated 2) Becomes darker 3) Becomes intense 4) Becomes less shallow 5) Becomes more complex 6) Becomes more profound 7) Becomes profound 8) Digs down further 9) Digs more 10) Does some dredging 11) Dredges 12) Gets lower 13) Gets more complicated 14) Gets more interesting 15) Gets more profound 1) Intensifies