In Conclusion

In conclusion, I would like to provide my evidence on how love affected the storyline:

1.  If not for Tessa's love of the Africans, she would not have been as determined (if at all) to fight against their abuse by KDH and the British High Commission.

2.  If not for Sandy's love for Tessa, Tessa would never have had any leverage to read the letter from Pellegrin which admitted Britain's involvement in the KDH scandal.  Also, the letter would have never been read at Justin's memorial, exposing the scandal to the world.

3.  If not for Arnold's supposed love for Tessa, Justin would have lost a central reason to investigate Tessa's murder.

4.  If not for Justin's love for Tessa, Justin would not have continued investigating Tessa's death.  Also, he would not have gone so far as to risk his life to finish her work.

These claims prove my thesis:

Love, at any cost, is essential to how the plot unfolds in The Constant Gardener.