  Perfectly controlled molecules are at the forefront of the quest to explore
chemical reactivity at ultra low temperatures. Here, we investigate for the
first time the formation of the long-lived intermediates in the time-dependent
scattering of cold bialkali $^{23}$Na$^{87}$Rb molecules with and without the
presence of infrared trapping light. During the nearly 50 nanoseconds mean
collision time of the intermediate complex, we observe unconventional roaming
when for a few tens of picoseconds either NaRb or Na$_2$ and Rb$_2$ molecules
with large relative separation are formed before returning to the four-atom
complex. We also determine the likelihood of molecular loss when the trapping
laser is present during the collision. We find that at a wavelength of 1064 nm
the Na$_2$Rb$_2$ complex is quickly destroyed and thus that the
$^{23}$Na$^{87}$Rb molecules are rapidly lost.
