Sinking into danger
When a sinkhole opens upand swallows one of Bayport s historicstatues, Frank and Joe suspect something or someone shady is at play.They jump at the chance to investigate: Joe as a member of an urbanexploration club and Frank as a photographer for the school paper.
But in the thick of their search, the boys stumble upon an entire undergroundcity that s been abandoned for years. Now the city is home to a cultish band ofcriminals who plan to take over Bayport. Frank and Joe are determined to catch the crooks . . . but afterbeing barreled down by a boulder and nearly squashed by a runaway train, they have to wonder: Are theyin over their heads?”