Disney TV scored a big hit in 2007, with Phineas and Ferb, the story of two mismatched stepbrothers who share a passion for fantastic adventures and a talent for creating high tech devices. Phineas Flynn is the American chatterbox; Ferb Fletcher is British and taciturn. The television movie Across the 2nd Dimension takes their antics further afield--and spoofs the mania for 3-D. When their giant shuttlecock collides with a spy plane piloted by their pet Perry the Platypus, Phineas and Ferb crash land in the laboratory of Dr. Doofenshmirtz. With typical enthusiasm (and blithe unawareness), the boys help the evil scientist build an "Otherdimensionator" that transports them to an alternate world. As the complications multiply, Perry is forced to reveal that he's not just a pet who grinds his teeth: he's Agent P, part of a cadre dedicated to fighting Doofenshmirtz's schemes. Eventually things get sorted out with the help of the alternate versions of Phineas, Ferb, and their sister Candace. Across the 2nd Dimension is most engaging when it plays like an extended episode of the series, with plenty of humor, off-beat songs, and pop-culture references: Doofenshmirtz and his alternate counterpart perform a number about finally finding a partner as the Blues Brothers, the Lone Ranger and Tonto, and Lucy and Ethel in the candy factory. As is often the case with TV cartoons that morph into features (Hey Arnold, Doug), things occasionally get too big--the swarms of CG robots the alternate Doofenshmirtz dispatches really don't add anything to the story. But the filmmakers generally succeed in walking a fine line, remaining smart without becoming smart alecks. Across the 2nd Dimension will delight Phineas and Ferb fans of all ages.