You Do Need power plug adapter while traveling from Brunei to Martinique.

Here is Why You Need An Adapter

The outlet and plug type used in Martinique are C, D and E and in Brunei is G. This is how they look like.

Brunei

In Brunei, outlets of type G are in use.

Type G

Martinique

In Martinique, outlets of type C, D and E are in use.

Type C

Type D

Type E