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Clark: Davis's ambulance number is 17.
Chloe: I'm surprised you haven't enrolled the services (get his phone?)
of our friendly Martian on the force. Of the army?
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Chloe is saying that the Martian has good services to offer or contribute, so she is surprised that Clark has not asked him to help.

The "force" refers to a team with some authority - such as police force. It could be used figuratively in this case..
Comments  
enrolled the services - used the assistance ("enroll" literally means to place on the roll, a list of registered members)

on the force - our force/group ("army" can be used, but it has a context of a very large group)
Students: Are you brave enough to let our tutors analyse your pronunciation?
 AlpheccaStars's reply was promoted to an answer.
Thanks, guys!