Off again and On again

There is a new team starting for a special task and one of our team members is being pulled to work on it. Initially I suggested that I be pulled instead but they wanted this particular persons credentials. Although my job share colleague and I were both asked if we could work more hours if necessary. We agreed then the next week I heard one of our team who had been pulled to help on another team might be helping this team member on the special task. Now it seems like wait five minutes and things will change because just before I left on last Wednesday I was asked if I would work on the task with the other team member. It seems that the other person wouldn't work out and it turns out that I would be the next logical choice. Huh? Well sure whatever, I can' wait to go in this week and find out what happened. Oh life in the flexible work force.