(define a (read-lines))
(pp a)
(define b (map string->list a))
(pp b)
(define c (map list->vector b))
(pp c)
(define d (map list->vector c))
(pp d)

OUTPUT

("...." "***." "....")                                                                                                                                       
((#\. #\. #\. #\.) (#\* #\* #\* #\.) (#\. #\. #\. #\.))                                                                                                      
(#(#\. #\. #\. #\.) #(#\* #\* #\* #\.) #(#\. #\. #\. #\.))                                                                                                   
                                                                                                                                                             
Error: (list->vector) bad argument type - not a proper list: #(#\. #\. #\. #\.)