You are a Medical Specialist. You are at once essential and useless, depending on your specialty. You are allowed to focus more tightly on your chosen specialty while other Medical Doctors work with the basics of patching up injured crewmembers. Generally, you have a specialty such as Cybernetics, Limb Transplants, Organ Transplants, or Anesthetics, which should guide the path of your career.
You spawn with a First-Aid Kit in Medbay just as any other doctor, but most specialties will require you to stay in or near the Operating Theater while on duty so that you can practice your discipline. Since you are not generally needed for routine Medbay treatment, you are more free to go grab a snack or shoot the breeze, as long as you respond to calls when issued.
Bare minimum requirements: If people need a specialist in your line of work, put down whatever you're doing and report to Medbay to carry out necessary tasks.
As a Medical Specialist, you have a specific focus that you should make sure your fellow doctors are aware of when you join a shift so they don't ask the neurosurgeon to graft cybernetic limbs, for example. However, as a member of the medical profession, you are still honorbound to heal people when they are hurt if you have nothing better to do and there aren't already doctors attending to the sick and wounded. 'Fortunately', every crewmember seems to think they know more about fixing injuries than you do, so you rarely get called upon to perform basic Doctor functions. Check the Medical Doctor page if you need a quick refresher.
As the primary thrust of most Specialists revolves around surgery, you'll get well acquainted with this room. Instruments require sterilization, and as a specialist you should know to wash your hands and wear clean gloves before working on a dirty patient. If you're an anesthesiologist, you'll also want to refill your N2O tank at the canister (and may be much busier than other specialists, depending on how many people need surgery). The Sterilizer will allow you to clean everything from jumpsuits to surgical tools.
Where surgeons and specialists go to shine. This room has surgical tools at the beginning of the round, but a bit of work from R&D will produce superior tools for surgery and other purposes. An observation chamber is adjacent to the theater so that you can suitably impress those who have gathered to watch your skill (generally, nobody, unless they're bored or Security watching over a dangerous patient.)
The guide to surgery is here.
So, you are a traitor? DON'T HIT SUICIDE JUST YET! There is so many wondrous, terrible things you can do. When people are injured, they are taken to medbay to be “doctored” by you and other people. You can then shoot them up with poisons, take them some place private in medbay and take what you want, or go for malpractice to end them. This is very good if you happen to be in a crowded area and stab the HoP and drag them back to Medical when people are in a panic. You can hide victims by putting little notes by morgue trays saying “This man has been borged” or “This man has been cloned” and no one will bat an eye at why they are naked, and why they are there (and often the chaplain will cremate them, or the chef will take some meat).
You are a Doctor. Your job is to help people - sometimes forcibly - and dealing with the fallout from the numerous violent calamities that inevitably descend on the station. You serve both as go-between for the station and large and the more specialized medical departments.
If you seek respect in this job, you have to go out of your way to earn it. But never forget the damage you can inflict on the unwary.