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                 exercise such rights.  If Purchaser pays the Purchase
                 Price by wire transfer of immediately available funds to a bank
                 account previously designated by Sellers on or prior to the
                 fifth business day after receipt of such notice by Purchaser,
                 then Sellers shall not be entitled to exercise any rights under
                 Section 4(b)(i)(B).

                 (iii)  Purchaser agrees that (A) the Escrow Agent is
                 authorized to conduct a sale of Zapata Shares as contemplated
                 under Section 4(b)(i)(B) to satisfy Purchaser's obligation to
                 Sellers, (B) such sales will be for the account of Purchaser
                 and are not being made by Sellers who will have no
                 responsibility with respect thereto, (C) Purchaser will remain
                 liable to Sellers in the event that the proceeds from such
                 sales are insufficient to pay the Purchase Price (including
                 interest) in full, (D) if for any reason Purchaser has failed
                 and/or is unable to take any and all actions required of it
                 under the SLA to enable the Escrow Agent to sell such Zapata
                 Shares and no Zapata Shares have been sold, it will promptly
                 notify Sellers and Sellers may elect to exercise their rights
                 under Section 4(b)(i) or may require Purchaser to do so
                 forthwith, and (E) until the earlier to occur of the payment
                 in full of the Purchase Price in immediately available funds
                 or the termination of this Agreement, the Escrow Agent will
                 continue to hold in escrow the certificate or certificates
                 representing the Envirodyne Shares and the Zapata Shares (less
                 certificates representing Zapata Shares sold in accordance
                 with Section 4(b)(i)(B) hereof).

         SECTION 5.  Escrow.  Simultaneously with the execution and delivery
hereof, the following actions shall be taken by the indicated parties:

         (a)     The Purchaser, the Sellers and the Escrow Agent shall execute 
an Escrow Deposit Agreement.

         (b)     The Sellers shall cause the Envirodyne Shares, which are held
in uncertificated form and identified on the books of Cede & Co. as being
registered to the Sellers, to be registered in the name of the Escrow Agent and
will provide such instructions to Cede & Co. as may be required to effectively
transfer the Envirodyne Shares to the Purchaser without any further action by
the Sellers.

         (c)     The Purchaser shall deliver to the Escrow Agent, for deposit 
into the Escrow Account, the stock certificate or certificates representing
2,500,000 shares of the common stock, par value $0.25 per share, of Zapata
Corporation ("Zapata"), a





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