The law is on their own planet .....
Be aware that when you have completed your work that does not
mean you get paid necessarily at that time. The legal system proceeds
at its own pace. Often, your check will come when the distribution is made (the case settles/court decision) which may be a year or more
your work is done.
So take that into consideration, if you are contracted you are one of the
consultants and others who will be paid when the money is distributed.
If this will be your sole source of income, ask the attorneys about
when you can expect your fee.