Tim Allen (left) and Spencer Breslin (right) star in the third and final installment in Allen’s Santa trilogy, opening today at Alderwood, Everett, Galaxy Monroe, Marysville, Mountlake, Olympic, Stanwood, Metro, Pacific Place, Woodinville, Cascade Mall and Oak Harbor. Santa (Allen), aka Scott Calvin, is faced with double-duty: how to keep his new family happy, and how to stop Jack Frost (Martin Short) from taking over Christmas. The movie is rated G. Look for Herald movie critic Robert Horton’s review in Saturday’s newspaper.