Just got to say - 40!

SELECT * FROM gallery2 WHERE topic_id="1158234" UNION SELECT * FROM gallery2 WHERE topic_id="48187" UNION SELECT * FROM gallery2 WHERE topic_id="1102470" UNION SELECT * FROM gallery2 WHERE topic_id="384148" UNION SELECT * FROM gallery2 WHERE topic_id="1041350" UNION SELECT * FROM gallery2 WHERE topic_id="828438" UNION SELECT * FROM gallery2 WHERE topic_id="1784023" UNION SELECT * FROM gallery2 WHERE topic_id="445538" UNION SELECT * FROM gallery2 WHERE topic_id="760539" UNION SELECT * FROM gallery2 WHERE topic_id="1771062" UNION SELECT * FROM gallery2 WHERE topic_id="1802946" UNION SELECT * FROM gallery2 WHERE topic_id="216190" UNION SELECT * FROM gallery2 WHERE topic_id="1432959" UNION SELECT * FROM gallery2 WHERE topic_id="824684" UNION SELECT * FROM gallery2 WHERE topic_id="1538776" UNION SELECT * FROM gallery2 WHERE topic_id="1557899"