  We study the asymptotics of the stationary sojourn time Z of a "typical
customer" in a tandem of single-server queues. It is shown that, in a certain
"intermediate" region of light-tailed service time distributions, Z may take a
large value mostly due to a large value of a single service time of one of
customers. Arguments used in the paper allow us to obtain also an elementary
proof of the logarithmic asymptotics for the tail distribution of the
stationary sojourn time in the whole class of light-tailed distributions.
