How To Extracting Data Into Three Table

This is my sample table Data

table1
TagID|TagName
--------------
1|xyz
2|123abc
3|a3bc
4|arsdew
5|xyc324
..............
..............

TagID--Primary Key

table2

TopicID|Topic
----------------
1|jkkj
2|kjgg
3|jhkj
4|refc
5|huhf
8|fyhj
9|jjk
...............
.............
..........
TopicID---Primary Key

table3
DetID|TagID|TopicID
-----------------------
1|1|1
2|1|2
3|1|3
4|2|4
5|2|5
8|3|8
9|3|9
....................
...................
.................

DetID---Primary key
TagID and TopicID----Foreign key


i need Topic based on TagName.


This xyz(TagName) have a 3 Topic. i need the 3 Topic

Once i select 123abc(TagName) that particular Topic I need..

any Query in Single Line.......................