Two of the biggest-ever names in fixed-income investing, Bill Gross and Jeffrey Gundlach, fierce rivals who had never previously talked, held a secret meeting over glasses of lemonade, water, and plates of crudites about whether to join forces. In the week of Sept. 15, just before Gross shocked the investment world on Sept. 26 by storming out of Pimco, he approached Gundlach and dropped a bombshell. According to Gundlach, Gross said he was about to be fired by the firm he had helped launch more than four decades ago and had built into a $2 trillion investment powerhouse.