As modified hereby, the Employment Agreement remains in full force and effect. This Waiver shall terminate in the event the Merger Agreement is terminated pursuant to Section 7.01 thereof or the Merger is otherwise abandoned. /s/ Laurence A. Lancit...

                              Waiver


     Reference  is made to the  Employment  Agreement  ("Employment  Agreement")
dated as of October 1, 1995  between  ▇▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇ (the  "Executive")  and
Lancit Media Entertainment ("Lancit").

     Reference is made to the Agreement and Plan of Merger ("Merger  Agreement")
among RCN Corporation ("RCN'), LME Acquisition Corporation ("LME") and Lancit.

     Pursuant to the Merger  Agreement,  LME, a wholly owned  subsidiary of RCN,
will be merged with and into Lancit  whereupon Lancit will become a wholly owned
subsidiary of RCN (the "Merger");

     In  consideration of RCN entering the Merger  Agreement,  (i) the Executive
hereby  agrees that he will not exercise his right to terminate  the  Employment
Agreement  under  Paragraph  8.F(2)  thereof  as a result of a Change of Control
(defined  in the  Employment  Agreement)  arising  pursuant to the Merger or any
other  transactions  contemplated by the Merger  Agreement,  including,  without
limitation,  approval of the Merger by Lancit's shareholders, and (ii) Executive
hereby waives any right to terminate the Employment  Agreement  under  Paragraph
8.F(2) by reason of any such Change of Control arising pursuant to the Merger or
any other transactions contemplated by the Merger Agreement,  including, without
limitation,  approval of the Merger by Lancit's  shareholders.  For avoidance of
doubt,  Paragraph  8.F(3)  will not  apply  to  termination  of the  Executive's
employment by Executive by reason of any such Change of Control arising pursuant
to the Merger or any other  transactions  contemplated by the Merger  Agreement,
including, without limitation, approval of the Merger by Lancit's shareholders.

     As modified  hereby,  the  Employment  Agreement  remains in full force and
effect.  This  Waiver  shall  terminate  in the event the  Merger  Agreement  is
terminated  pursuant  to  Section  7.01  thereof  or  the  Merger  is  otherwise
abandoned.
                                    /s/ ▇▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇
                                    ---------------------------------
                                    ▇▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇

                                 RCN CORPORATION

                               By: /s/ ▇▇▇▇ ▇▇▇▇▇▇▇ 
                                  -------------------------------------------
                                      Name: ▇▇▇▇ ▇▇▇▇▇▇▇
                                     Title: Executive Vice President

                               LANCIT MEDIA ENTERTAINMENT, LTD

                               By: /s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                  -------------------------------------------
                                      Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
                                     Title: Chairman of the Board and Chief 
                                              Executive Officer