Gustave has taken it upon himself to observe Marion and Sanglain following the death of the Princess and DT.   But KT thinks Gustave is in the city of Marquesas for other reasons. 
Judging from their strides, 
they have a destination.
Juzgando por su paso, tienen un destino.
Juzgando por su paso, tienen un destino.
A julgar pela passada,
eles têm um destino.