AGREEMENT

                             AGREEMENT


     Reference is made to the Employment  Agreement  dated as of March 31, 1997,
as amended (the "Employment  Agreement") between Xxxxx Xxxxxxx ("Executive") and
Lancit Media Entertainment, Ltd. ("Lancit").

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

     Executive,  Lancit, RCN, and LME (collectively,  the "Parties") agree that,
contingent on the  occurrence  of the  Effective  Time, as defined in the Merger
Agreement, the following shall occur:

     1.   Effective upon the Effective  Time, and subject to Item 2 hereof,  the
          Employment  Agreement shall be terminated and the rights,  duties, and
          obligations of the Parties thereunder shall be cancelled;

     2.   The Parties  acknowledge  that,  upon and subject to the occurrence of
          the Effective Time,  Executive is entitled to receive $750,000 in cash
          pursuant to the terms of her Employment Agreement. RCN agrees to grant
          and  Executive  agrees to accept,  in lieu of such cash  amount and in
          complete  satisfaction  of any and all  rights  under  her  Employment
          Agreement, as of the Effective Time, a grant of shares of common stock
          of RCN  registered  under  the Form S-8  covering  RCN's  1997  Equity
          Incentive  Plan and having a fair market value based on RCN's  closing
          price  the day  before  the  Effective  Time  equal to  $750,000  (the
          "Shares"). Immediately following the Effective Time, RCN shall deliver
          to  Executive  the stock  certificates  for the Shares  which shall be
          freely transferable  subject to Rule 144, if applicable,  and Rule 145
          of the  Securities  Act of 1933  and  subject  to no other  terms  and
          conditions.

     Executive  acknowledges  that she is  entering  into this  Agreement  as an
inducement for RCN to enter into the Merger  Agreement and that in the event the
Merger fails to occur, this Agreement shall be null and void.



Dated:     2/27/98              /s/ XXXXX XXXXXXX
      ----------------         ------------------------------
                                       XXXXX XXXXXXX



                                       RCN CORPORATION

Dated:     2/27/98          By: /s/ XXXX XXXXXXX
      ----------------         ------------------------------
                               Name: Xxxx Xxxxxxx
                               Title:Executive Vice President

                               LANCIT MEDIA ENTERTAINMENT, LTD.

Dated:     2/27/98          By: /s/ XXXXX X. XXXXXXX
      ----------------         ------------------------------
                               Name: Xxxxx X. Xxxxxxx
                               Title: Chairman of the Board and Chief 
                                        Executive Officer

                               LME ACQUISITION CORPORATION

Dated:     2/27/98           By:/s/ XXXX XXXXXXX
      -----------------         -----------------------------
                                Name: Xxxx Xxxxxxx
                                Title:Executive Vice President