Columbia Pictures and producer Laurence Mark have made a preemptive acquisition of the upcoming Robert Crais novel “Demolition Angel” for $525,000 against $1 million, with Crais aboard to script his thriller.Story revolves around a female bomb squad detective and a male ATF agent chasing a serial bomber. The Ballantine novel will be published in May. Crais is a former TV writer on shows including “Hill Street Blues” and “Cagney and Lacey” who as an author is best known for the mystery series featuring private eye Elvis Cole. The sale of “Demolition Angel” is something of a surprise, if only because Crais has steadfastly declined king-sized offers for Elvis, both as movies and TV series. He’s written eight of those novels, the last of which was “L.A. Requiem.” “Demolition Man” was his first non-Elvis effort. The book was brought in by Mark exec Jonathan King and bought preemptively, an encounter made possible by Mark’s vain attempt to buy the Elvis books. “I feel like that series is my life’s work, and I’ve turned down about 19 or 20 offers since 1987,” said Crais, who has been around long enough to see other author’s creations go awry on the screen. “Larry wanted to buy Elvis for a TV series, which I thought would be wholly inappropriate for Elvis, but he admired the language and the work, and I admired the films he’s produced. We gave him this book and he bought it.” Will Crais consider allowing Elvis to reenter the building? “If this yields a picture I’m proud of, it’s conceivable that after 20 turndowns something could happen.” Crais is repped by Broder Kurland Webb Uffner’s Tricia Davey, Emile Gladstone and Norman Kurland, working with lit agent Aaron Priest. “ER” ROTATION COMING UP SHORT:The ever-evolving cast of NBC’s “ER” is about to change once again. Dish hears that Kellie Martin, who’s halfway through her second season as medical student Lucy Knight, has formalized an exit during the second half of this season. The show is keeping the exact time and circumstances of her exit quiet, though sources said the parting is part of the storyline and it’s electric. Sources close to the actress said she wanted to pursue other opportunities because her character wasn’t evolving with all the other new characters vying for camera time. Her exit was agreed upon after several meetings with producers. “ER” has kept its hold as the top-rated drama despite the exit of several longtime castmembers, including the pending exit of Julianna Margulies, who nixed a contract extension worth $27 million. Martin’s agent, Gersh’s Lorrie Bartlett, will look for another series or pic for Martin, who spent seven seasons on “Life Goes On.” “ER” exec producers John Wells and Lydia Woodward confirmed Martin’s exit, saying in a statement, “working with Kellie has been a joy and we wish her well. She will be missed next season and we hope to have an opportunity to work with her in the future.” COL MAKING TRAVEL PLANS? John Travolta owes Columbia a picture as part of the settlement for bailing out of the Roman Polanski-directed “The Double,” and the studio’s hoping he’ll make it “Travel Agent,” a Gregory Hansen-scripted drama in which a man time-travels six months to thwart an assassination. Dish hears that Andy Davis, who’s directing Arnold Schwarzenegger in “Collateral Damage,” wants to helm it. Travolta’s expected next to star in “Steinbeck’s Point of View” pending the hiring of a director by Bel Air, and sources said “Travel Agent” is a viable followup. Travolta nearly satisfied the Col slot with plans to star with wife Kelly Preston on “The Shipping News,” but both dropped out of the adaptation of the Pulitzer Prize-winning Annie L. Proulx novel. HUGHES INTRIGUE CONTINUES: In the continuing effort to turn Howard Hughes into a Hollywood biopic, a tantalizing possible teamup has emerged: Edward Norton as the billionaire aviator-turned recluse, directed by two-time Oscar winner Milos Forman, scripted by “People Vs. Larry Flynt” and “Man on the Moon” scribes Scott Alexander and Larry Karaszewski. While those players have barely met on the project, they’re all intrigued, Dish hears. For those keeping score at home, Michael Mann and Leonardo DiCaprio are aligned with a Disney project scripted by John Logan; Warren Beatty has long pined to do a biopic, and Allen and Albert Hughes set one up with Johnny Depp, though the latter project is a late scratch. The project being considered by the Norton team is based at Arnon Milchan’s New Regency with Charles Evans Jr. producing and is contingent on whether the producer formally aligns with Disney on the Mann-DiCaprio project. Norton and Forman couldn’t be reached, but Alexander and Karaszewski acknowledged they’ve been approached. Aside from just starting work on a Marx Brothers biopic for Universal and Jersey, which they will direct, the duo is understandably wary of entering a competition. “Ten years ago we would have said how can you go up against Warren Beatty, and now it’s, how can you go up against Michael Mann and Leonardo,” said Alexander. “As writers, the problem is we’d have to spend the year working hard before finding out the project across the street has gotten a greenlight and we’ve wasted our time. With both Andy Kaufman and Larry Flynt, we knew we were the only ones,” added Karaszewski.