You might say that Walter Lord provoked the whole Titanic mania by interviewing dozens of survivors and fashioning their reminiscences into the classic non-fiction novel A Night to Remember, which was made into a 1958 film that heavily influenced James Cameron's 1998 epic. Some of the dialogue is more vivid than the 1998 film--when a kid sees the deadly iceberg, he says excitedly, "Oh, Muddie, look at the beautiful North Pole with no Santa Claus on it." But much has been discovered since Lord's original book made waves--such as the shipwreck itself, and a wealth of scientific inquiry. So he wrote this semisequel, which tackles each of the remaining mysteries about the unnecessary calamity in a methodical, but quite readable, fashion. How come the wireless operators blew it so fatally? Maybe they would have had better operators if they paid them more than $5 a week--as Lord notes, it would have taken a wireless operator 18 years to earn one transatlantic ticket. How come the Californian just sat there in nearby waters and neglected to save anyone on the frantically signaling and flare-firing Titanic? Lord quotes a man on the nonsinking ship admitting to "a certain amount of slackness," which he uses for a sardonic chapter title. Some of the characters are more sympathetic, such as Renee Harris, who used the money she won suing the Titanic owners for her husband's death to bankroll neophyte playwright Moss Hart's first show. Lord says