Dynamic variables and lists

Here's my problem:

% set a power
power
% set ${a} [list a b c d]
a b c d
% set second [lindex ${a} 1]
% puts $second
# prints nothing
% set second [lindex eval ${$a} 1]
can't read "$a": no such variable
% puts $a
power
% set second [lindex eval $a 1]
bad index "power": must be integer or end?-integer?

How do I get access to the $power list without specifying "power" ?

Any help is appreciated. Thanks.

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