Later that spring, in front of the Burnet House hotel in Cincinnati, sportswriter Harry Weldon of the Enquirer came upon Bergen in a "jolly good humor" and asked him what he thought of the pennant race. "Why, we will win the pennant in a gallop," boasted Bergen. "It's a cinch for us!" Then, Weldon would recall in The Sporting News the following January, a scowl came over Bergen's face. "But it won't make a damned bit of difference to me whether they win or not," he said.
"Why not?" asked Weldon.
"Because I won't be with this bunch much longer," Bergen said. "I am going to quit them. I am tired of traveling with a lot of knockers and backbiters. They are all giving me the worst of it. I'll shake the gang just as soon as we get to Boston."
Frank Killen, the Boston pitcher, was listening as Bergen spoke. Other teammates soon gathered around, and Bergen stopped talking. Ten minutes later, Weldon was talking to the manager, Selee, when Killen came over, took Weldon aside and said, "Marty is out there crying like his heart would break. He sent me here to ask you not to put anything in the paper about what he told you." Weldon promised. Then Killen turned to Selee and asked what the trouble was with Bergen.
"He is insane," Selee said. "I've done everything in my power to get along with him. He is possessed of the insane idea that none of us like him. I will have to get rid of him. He is the greatest catcher in the business, but...there is no use trying to keep him on the team."
Soden, the Beaneaters' president, had warned Selee that Bergen was dangerous and, he feared, might shoot someone. Players thought that Bergen was growing more and more detached from reality. Some attributed his eccentricities to drink, but he was known to be a temperate man and never hung out in saloons on the road, reading in his room after dinner rather than carousing with the boys. When the team played at home, Bergen, rather than stay at a hotel in Boston, commuted by train from North Brookfield.
In July, on their way to Cincinnati at the beginning of a long western road trip, the Boston players were gathered in groups in their special car, laughing and playing cards as Bergen brooded alone in a corner. The train stopped briefly in Washington, D.C. Suddenly, a New York player, whose team also had a special car hitched to the train, dashed into the Boston car and asked what was going on with Bergen. "We looked about the car, but could see nothing of him," Kid Nichols later recalled. "Then someone told us to look out on the platform. There was Bergen, with his grip in his hand, walking away from the train as fast as possible. Our train had started so we could not stop."
It would be the longest and most spectacular walkout of Bergen's career, and it infuriated the Bostons because it left them, as they contended for their third pennant in a row, with only their backup to catch game after game in the midsummer heat. The Boston Globe's T.H. Murnane, a former player who had become the most respected of the nation's baseball writers, journeyed to Bergen's farm in late July to get the story and found the shed full of hay, the corn crop healthy and Bergen standing in the barn doorway with little Florence and Joe. He complained to Murnane of all the catching he had done, of his shattered nerves, of his need for rest.
Two years before, following the '97 season, Bergen had told Murnane, "Many a time I have asked for a leave of absence simply because I thought I would go mad if I worked another day without rest." Now Bergen told the reporter, "Manager Selee would never listen to my reasons for coming home, always turning me off with the remark, 'That will cost you fifty dollars; you can't give me any stories.' At Chicago, on the last trip, at least four members of the Boston team went out of their way to abuse me every time I went to bat. They would call out, 'Strike him out!'...I left the club when it reached Washington.... I found manager Selee and the rest of the players were trying to avoid me."
Bergen's return to Boston, on Aug. 4, a little more than two weeks after he had left, unexpectedly was the crowning moment of his career. Against the Washingtons, Bergen nailed all three runners who tried to steal on him. The fans gave him an ovation every time he came to bat. In the ninth inning, with two out, the Bostons down 3-2 and men on second and third, Bergen drove a single to left mat scored both runners and won the game. Fans vaulted the barricades at South End Grounds to shake Bergen's hand and pound him on the back. Wrote Murnane, "After the game Bergen was a mark for the crowd, who cheered him until he went out of sight."