 The children learn that A Lady Writing was traveling from The National Gallery of Art in Washington D.C. to Hyde Park . The next day there is a story in the paper of how the painting mysteriously disappeared . A letter from the thief appears in the newspaper , telling the public that he will not give back A Lady Writing until they prove which Vermeer paintings were truly painted by him . This sparks worldwide uproar . Calder and Petra investigate as their friendship grows . Mrs. Sharpe requests police protection and it is revealed that she and Ms. Hussey were two of the three recipients of the thief 's letter . Calder and Petra eventually conclude that the painting is hidden in the local Delia Dell Hall , and they sneak out and find it . They barely escape from the thief , who is later found dead from a massive heart attack on the train by the police . They learn that the man is Xavier Glitts , also knowned as Glitter Man , who was posing as Tommy 's stepfather under the name Fred Steadman . A known art thief , he was asked to steal the painting and sell it for sixty million dollars . The other recipient of the letter is revealed to be Mr. Watch . 
 The children learn that A Lady Writing was traveling from The National Gallery of Art in Washington D.C. to Hyde Park . The next day <a href='dey_it' title='1'><mark>there</mark></a> is a story in the paper of how the painting mysteriously disappeared . A letter from the thief <a href='uninflect' title='2'><mark>appears</mark></a> in the newspaper , telling the public that he will not give back A Lady Writing until they prove which Vermeer paintings <a href='uninflect' title='3'><mark>were</mark></a> truly painted by him . This <a href='uninflect' title='4'><mark>sparks</mark></a> worldwide uproar . Calder and Petra investigate as their friendship <a href='uninflect' title='5'><mark>grows</mark></a> . Mrs. Sharpe <a href='uninflect' title='6'><mark>requests</mark></a> police protection and it is revealed that she and Ms. Hussey <a href='uninflect' title='7'><mark>were</mark></a> two of the three recipients of the thief <a href='null_genetive' title='8'><mark>'s</mark></a>letter . Calder and Petra eventually conclude that the painting is hidden in the local Delia Dell Hall , and they sneak out and find it . They barely escape from the thief , <a href='null_relcl' title='9'><mark>who</mark></a>is later found dead from a massive heart attack on the train by the police . They learn that the man is Xavier Glitts , also knowned as Glitter Man , <a href='null_relcl' title='10'><mark>who</mark></a>was posing as Tommy <a href='null_genetive' title='11'><mark>'s</mark></a>stepfather under the name Fred Steadman . A known art thief , he was asked to steal the painting and sell it for sixty million dollars . The other recipient of the letter is revealed to be Mr. Watch . 
Da children learn that A Lady Writing was traveling from TdaNational Gallery of Art in Washington D.C. to Hyde Park . The next day it is a story in the paper of how the painting mysteriously disappeared . A letter from thdahief appear in the newspaper , telling the public that he gon not give back A Lady Writing until they prove which Vermeer paintings was truly painted by em . This spark worldwide uproar . Calder and Petra investigate as their friendship grow . Mrs. Sharpe request police protection and it is revealed dat she and Ms. Hussey was two of thedaree recipients of the thief  letter . Calder and Petra eventually conclude tdatthe painting is hidden in the local Delia Dell Hall , and they sneak out and find it . They barely escape from the thief , is later found dead from a massive heart attack on the dain by the police . They learn that the man is Xavier Glitts , also knowned as Glitter Man , was posing as Tommy  stepfather under the name Fred Steadman . A known art thief , he was asked to steal the painting and sell it for sixty million dollars . The odar recipient of the letter is revealed to b Mr. Watch .