WILMER CUTLER PICKERING
HALE AND DORR LLP [LETTERHEAD]

December 10, 2004



Pioneer Series Trust II
60 State Street
Boston, MA 02109

Safeco Common Stock Trust
5069 154th Place N.E.
Redmond, Washington 98052


Ladies and Gentlemen:

This opinion is being delivered to you in connection with the Agreement and Plan
of Reorganization (the "Agreement") made as of October 29, 2004 by and between
Pioneer Series Trust II, a Delaware statutory trust, on behalf of its series,
Pioneer Growth Opportunities Fund ("Acquiring Fund"), and Safeco Common Stock
Trust, a Delaware statutory trust, on behalf of its series, Safeco Growth
Opportunities Fund ("Acquired Fund"). Pursuant to the Agreement, Acquiring Fund
will acquire all of the assets of Acquired Fund in exchange solely for (i) the
assumption by Acquiring Fund of all of the Assumed Liabilities, as defined in
the Agreement (the "Acquired Fund Liabilities"), and (ii) the issuance of
Investor Class shares of beneficial interest of Acquiring Fund (the "Acquiring
Fund Shares") to Acquired Fund, followed by the distribution by Acquired Fund,
in liquidation of Acquired Fund, of the Acquiring Fund Shares to the
shareholders of Acquired Fund and the termination of Acquired Fund (the
foregoing together constituting the "Transaction"). All section references,
unless otherwise indicated, are to the United States Internal Revenue Code of
1986, as amended (the "Code").

In rendering this opinion, we have examined and relied upon (i) the prospectus
for Acquiring Fund dated December 10, 2004; (ii) the statement of additional
information for Acquiring Fund dated December 10, 2004; (iii) the prospectus for
Acquired Fund dated April 30, 2004, as supplemented on August 2, 2004 and August
3, 2004; (iv) the statement of additional information for Acquired Fund dated
April 30, 2004, as revised on August 19, 2004; (v) the Notice of Meeting of
Shareholders Scheduled for December 8, 2004 and the accompanying proxy statement
and prospectus on Form N-14 (the "Proxy Statement"); (vi) the Agreement; (vii)
the tax representation certificates delivered pursuant to the Agreement and
relevant to this opinion (the "Representation Certificates"); and (viii) such
other documents as we deemed necessary or relevant to our analysis.

In our examination of documents, we have assumed the authenticity of original
documents, the accuracy of copies, the genuineness of signatures, and the legal
capacity of signatories. We have

       BALTIMORE    BEIJING    BERIN    BOSTON    BRUSSELS    LONDON
  MUNICH    NEW YORK    NORTHERN VIRGINIA    OXFORD    WALTHAM    WASHINGTON



assumed that all parties to the Agreement and to any other documents examined by
us have acted, and will act, in accordance with the terms of such Agreement and
documents and that the Transaction will be consummated pursuant to the terms and
conditions set forth in the Agreement without the waiver or modification of any
such terms and conditions. Furthermore, we have assumed that all representations
contained in the Agreement, as well as those representations contained in the
Representation Certificates are, on the date hereof, and will be, at the
consummation of the Transaction, true and complete in all material respects, and
that any representation made in any of the documents referred to herein "to the
knowledge and belief" (or similar qualification) of any person or party is, and
at the consummation of the Transaction will be, correct without such
qualification. We have also assumed that as to all matters for which a person or
entity has represented that such person is not a party to, does not have, or is
not aware of any plan, intention, understanding, or agreement, there is no such
plan, intention, understanding, or agreement. We have not attempted to verify
independently any of the above assumptions or representations.

The conclusions expressed herein represent our judgment regarding the proper
treatment of the Transaction under the income tax laws of the United States
based upon the Code, case law, Treasury Regulations, and the rulings and other
pronouncements of the Internal Revenue Service (the "Service") in effect on the
date of this opinion. No assurances can be given that such laws will not be
amended or otherwise changed after the consummation of the Transaction or that
such changes will not affect the conclusions expressed herein. Nevertheless, we
undertake no responsibility to advise you of any developments after the
consummation of the Transaction in the application or interpretation of the
income tax laws of the United States.

Our opinion represents our best judgment regarding how a court would decide if
presented with the issues addressed herein and is not binding upon the Service
or any court. Moreover, our opinion does not provide any assurance that a
position taken in reliance on such opinion will not be challenged by the Service
and does not constitute any representation or warranty that such position, if so
challenged, will not be rejected by a court.

This opinion addresses only the specific United States federal income tax
consequences of the Transaction set forth below, and does not address any other
federal, state, local, or foreign income, estate, gift, transfer, sales, or
other tax consequences that may result from the Transaction or any other action
(including any action taken in connection with the Transaction).

On the basis of and subject to the foregoing and in reliance upon the
representations, facts and assumptions described above, we are of the opinion
that the acquisition by Acquiring Fund of the assets of Acquired Fund solely in
exchange for the issuance of Acquiring Fund Shares to Acquired Fund and the
assumption of the Acquired Fund Liabilities by Acquiring Fund, followed by the
distribution by Acquired Fund, in liquidation of Acquired Fund, of Acquiring
Fund Shares to Acquired Fund shareholders in exchange for their Acquired Fund
Shares and the termination of Acquired Fund, will constitute a "reorganization"
within the meaning of Section 368(a) of the Code. No opinion is expressed or
implied regarding the tax consequences of any other aspects of the Transaction
except as expressly set forth above.



This opinion is being delivered to you solely in connection with the closing
condition set forth in Section 8.5 of the Agreement. This opinion is intended
solely for the benefit of you and the shareholders of the Acquired Fund and it
may not be relied upon for any other purpose or by any other person or entity,
and may not be made available to any other person or entity, without our prior
written consent.



                                         Very truly yours,

                                         WILMER CUTLER PICKERING
                                         HALE AND DORR LLP


                                         By:      /s/ Roger M. Ritt, Partner
                                                  --------------------------
                                                  Roger M. Ritt, Partner